How to Tell If Turquoise Is Real
Real turquoise is a copper aluminum phosphate — 4 to 6.5 on the Mohs scale. Three checks matter: matrix that runs through the stone rather than sitting on its surface, a price that fits the grade, and a seller who names the mine and the treatment. Most home tests are folklore.
What real turquoise actually is
Turquoise is a hydrated copper aluminum phosphate — CuAl6(PO4)4(OH)8·4H2O. It is a secondary mineral, which is the part most people miss. It doesn't crystallise into a bed of its own. It gets carried in solution and deposited into pockets and crevices that were already there, in faulted and fractured zones of weathered rock at the water table's edge. That is why turquoise comes out as nuggets and veins rather than crystals: the stone takes the shape of the crack it filled.
It is a desert gem in the literal sense. Deposits sit between roughly 3,000 and 8,500 feet, on low, unremarkable hillsides in dry country, most often within, near, or above copper and gold deposits. A miner reads the ground for iron-stained limonite, chalcedony, and quartz at the outcrop.
The matrix is the host rock. The brown, black, or golden webbing in a stone is the rock the turquoise grew in, and its pattern is a record of how the pocket was shaped: the more the host rock was broken up and the more evenly the turquoise solution spread through it, the more likely you get the fine spiderweb that collectors chase. Matrix is not damage. It is the stone's address.
Hardness runs 4 to 6.5 on the Mohs scale. Lowry gives 4 to 6.5 for usable natural turquoise, and 4.5 to 6.5 for the polish-grade fraction specifically — worth knowing both numbers, because you'll see each quoted. And here is the figure that explains the entire turquoise market: only about 15 percent of the world's turquoise production comes out of the ground hard enough to grind, shape, and take a polish. The other 85 percent is soft, pale material the trade calls chalk — some of it soft enough to write on a chalkboard. Hold onto that number. Everything in the next section follows from it.
Colour is a question of where the stone was dug. Compare blue against blue and green against green; several famous mines produce green and are collected hard on their own terms. Be sceptical of tidy chemistry stories about what makes a stone green — turquoise sits in a group of near-identical minerals that differ by a single element, and these get identified incorrectly even in a lab. The honest answer is that colour is a function of the deposit. To understand why the mine a stone came from matters so much, start there.
Real, stabilized, dyed, imitation: the honest taxonomy
Eighty-five percent of what comes out of a turquoise mine is too soft to cut. That single fact is why this vocabulary exists, and why anyone who tells you stabilized turquoise is a scam is selling you something.
Natural. Cut, shaped, and polished with nothing added. The hard 15 percent — the material hard enough to take a polish without falling apart or burning on the wheel.
Stabilized — the same thing as treated; the two words describe one process. Soft, porous stone is soaked and cured in liquid plastic, usually a polyester resin. The resin hardens in the pores, and the stone comes out tougher and more compact. It also comes out darker, for a reason worth understanding: the resin makes the stone less porous and more translucent, the way a wet patch on cloth reads darker than the dry cloth around it. If the turquoise is blue, it gets bluer; green, it gets greener. No dye is added. The bond is permanent, and the stone then resists oils and detergents — which is why stabilized turquoise is often the more practical stone to wear daily. This is not a lesser stone dressed up. It is real turquoise, made wearable. Say so.
Oiled or waxed. Softer material finished in oil- or wax-based polish. It looks good on the shelf and it does not hold: these stones lose or shift colour as the oils break down in sunlight and changing temperature, and they readily absorb whatever else they touch. A dull, waxy surface is one of the few visual flags that genuinely means something.
Dyed. Colour added. The distinguishing failure is that dye is not stable — the colour breaks down over time with direct sunlight or changing temperatures. Stabilization is permanent; dye fades. That is the line between the two.
Imitation — not turquoise at all:
- Howlite and magnesite. Naturally white minerals, dyed to imitate turquoise. The most common fake you will meet.
- Block / reconstituted. Mineral compositions pressed or moulded together with a plastic binder, with rock, sand, pyrite and colour added to imitate matrix. The tell: soft enough to be scratched easily with a knife blade.
- Plastic and glass. Plastic coloured with blue pigment; glass cabochons going back centuries. The Southwest's most famous glass imitations are the Hubbell beads, traded through the Hubbell Trading Post near Ganado, Arizona — glass made to pass as turquoise.
- Gilson. A lab synthetic developed by Pierre Gilson in the 1970s, made to the clarity and robin's-egg blue of Persian turquoise, later with a black matrix added. Sold worldwide.
The one that matters most: a fake can wear a matrix. Pyrite and dye get added to plastic specifically to counterfeit that webbing, and processed chalk can be given matrix in the treating. Matrix is a real clue and it is not proof.
How to actually tell, and which tests are folklore
Start here, because it saves everyone time: there is no reliable home test. No single patch test identifies the condition of every turquoise on the market, and visual expertise is only as good as the source of the knowledge behind it.
The checks that hold up:
- Ask what mine it came from, and what was done to the stone. This is the strongest check available to a buyer, and it costs nothing. A seller who knows their material can answer both. One who deflects has told you something.
- Get it in writing. Reputable dealers guarantee a purchase in writing. A verbal "it's natural" is not a disclosure.
- Read the surface, not the shine. A high polish proves nothing — polish depends on the lapidary's wheel, not the stone's honesty. But a dull, waxy surface is a genuine flag that a stone may have been oiled or waxed rather than cut hard.
- Read the matrix knowing its limits (see above). Pattern that sits on a stone rather than running through it is the thing to catch.
- Sanity-check the price against the claim — see the next section.
- Pick it up, and look at the back. Our practice at the counter, not a lab test: real stone and solid silver carry weight, and a set stone sits in a bezel while a glued one hides its edges.
The tests you've read about that don't work:
| Test | Verdict |
|---|---|
| Tooth / bite test | Folklore. Too many variables — stone size, thickness, setting — for the sound or feel to mean anything. |
| Temperature / "real stone feels cooler" | Folklore, explicitly. Showcase lights, sunlight, and your own body temperature all swamp the signal. |
| Taste test | Not just useless — there are rumours of dealers contracting hepatitis from it. Don't. |
| Scratch / hardness test | Cannot separate natural from treated: treated stone runs 4–5, natural 4–6.5. The ranges overlap. It only damages the stone. |
| Acetone test | Not in our sources. We won't cite it. |
| "It's pawn, so it's real" | Pawn means an item was pawned. Nothing more. It says nothing about whether the stone is natural, treated, plastic, or glass. |
| Hot pin | Works only on cheap plastic. Ineffective on most imitations, and it destroys the piece. |
| Grinding for the plastic smell | Real, and destructive — it detects plastics and waxes but not oiled or enhanced stone. A lapidary's test, not a buyer's. |
If a page recommends a test that damages a stone you already own, it isn't advice. When you're ready to verify who made a piece, the hallmark on the back is where you start.
What real turquoise should cost
No honest page can give you a price per carat, because turquoise isn't priced like diamonds. There is no universal grading lab. Price is set by five things: condition, source, colour, clarity, and matrix.
- Source does heavy lifting. A named mine functions the way a certificate does elsewhere, and the famous mines each carry their own grading system — a high-grade Bisbee is judged on different terms than a high-grade Number Eight. Which is precisely why the name is worth stealing. Mexican turquoise has been misrepresented and sold as Kingman since before the 1970s, and Mexican and Chinese stone has moved by the ton under the names Morenci, Sleeping Beauty, Lander Blue, and Lone Mountain. Treat a mine name as a claim, not a credential: a buyer who wants stone from a classic mine needs a written guarantee of the source, from the miner and the seller both.
- Darker is rarer. The deepest colours are the hardest to find, so they carry the most value — but compare within a colour, blue to blue and green to green.
- Treated material is cheap to produce, and should be priced that way. It comes from the soft fraction that would otherwise be unusable — possibly 80 percent of all turquoise mined — and the process is not expensive. Treated turquoise should not command prices anywhere near untreated stone. Not because it's shameful. Because it's abundant.
The trap runs in both directions. A price far under the market is a flag. But the more dangerous case is the opposite: when the intent is to deceive, the imitation is priced close to the natural gemstone — because a realistic price is what makes the lie work. Add the perennial tourist-trade tell: the shop in a continuous going-out-of-business sale. The reliable signal is not the number. It is whether the number comes with a source.
How T.Skies discloses every stone
We tell you what the stone is, where it came from, and what was done to it. Not as a courtesy — as the baseline the law already sets and most of this trade ignores. The FTC Jewelry Guides (16 CFR Part 23) are specific: under §23.24, a seller must disclose that a gemstone has been treated when the treatment isn't permanent, when it creates special care requirements, or when it significantly affects the stone's value. Stabilized turquoise routinely meets that last condition; oiled or waxed stone meets all three. §23.1 makes misrepresenting a product's treatment, origin, or value deceptive on its face. And §23.27 bars the words real, genuine, and natural for anything produced artificially — words this trade throws around freely.
What that looks like on our listings:
- The stone. Natural, stabilized, or otherwise — stated, not implied.
- The source. Our turquoise comes principally from named mines such as Kingman, the Mineral Park ground in Mohave County, Arizona; Royston, in Esmeralda County, Nevada, where the name covers several neighbouring deposits worked as one district; and Campitos, in Mexico. We name that last one as Mexican turquoise because the lie in this trade runs the other direction. Our primary stone supplier is Toltec Turquoise. Ask which mine a particular stone came from — that's a question we can answer.
- The maker. Every gallery piece is stamped with the maker's name or hallmark, and listed with the artist's name and tribal affiliation, with their permission. On collaboration pieces bearing both an artist's hallmark and the TSKIES hallmark, the listing says so.
None of this requires trusting us. It requires knowing what to ask. The hallmark on the back is in our hallmark guide, and the maker has an entry in our silversmith directory.
Frequently asked questions
How can I tell if turquoise is real?
Ask what mine it came from and what was done to the stone, and get the answer in writing. Then look at the stone: matrix should run through it, not sit on the surface, and a dull waxy finish suggests oiled or waxed material. There is no reliable home test — the tooth, temperature, and scratch tests are folklore, and the scratch test can't tell natural from treated because their hardness ranges overlap.
Is stabilized turquoise real turquoise?
Yes. Stabilized turquoise is real stone that has been soaked and cured in resin so it's hard enough to cut and wear. Only about 15 percent of mined turquoise is hard enough to use untreated; stabilization is what makes the rest wearable. It should be disclosed, and it should be priced below natural stone — but it is not a fake.
What's the difference between stabilized and dyed turquoise?
Stabilization adds resin, not colour — the stone darkens because it becomes less porous, the way wet cloth reads darker than dry. The bond is permanent. Dye adds colour, and it isn't stable: dyed stone fades with sunlight and changing temperature.
What is the most common fake turquoise?
Dyed howlite and magnesite — white minerals coloured to imitate turquoise. Also common: block or reconstituted material, which is mineral powder pressed with a plastic binder, often with sand and pyrite added to counterfeit matrix. It scratches easily with a knife blade.
Does the matrix prove turquoise is real?
No. Matrix is the host rock the turquoise formed in and it's a useful clue, but plastic imitations have pyrite and dye added specifically to fake it, and treated chalk turquoise can be given matrix in processing. Read matrix alongside source and price, never alone.
How hard is turquoise on the Mohs scale?
4 to 6.5. Softer than quartz, which is why turquoise scratches and why it should be kept away from oils, lotions, and abrasives. Hardness won't tell you whether a stone is treated — treated turquoise runs about 4 to 5, well inside the natural range.
From the Library: Pogue, The Turquois (1915)
1915 primary source. Anything described as current here describes 1915, not today.
On why turquoise comes as veins and nuggets, Pogue (1915) noted:
“Turquois is almost exclusively massive, and until 1911 no crystallized examples of this mineral were known.”
— Pogue (1915), p. 24
Pogue (1915, p. 23) credited copper for turquoise's color and thought iron probably modified the shade, but wrote that the popular idea that copper makes the blue and iron makes the green could not be regarded as thoroughly established.
Pogue (1915) summarized W. T. Schaller's finding on turquoise's closest relative:
“The important relation therefore is brought out that chalcosiderite differs from turquois in having ferric iron in the place of alumina.”
— Pogue (1915), p. 27
Writing in 1915, Pogue reprinted the seventeenth-century English writer Thomas Nicols, who opened his section on turquoise with a warning:
“Many strange things beyond faith are reported concerning the vertues of this stone, which nothing but excesse of faith can believe.”
— Pogue (1915), p. 121
Nicols's own tests for the real thing, as Pogue (1915) reprinted them, began with a color change by candlelight:
“the true Turchoys is known by the change of its colour; in the daytime it is excellently ceruleous or skie coloured; at night time by candle light it is green.”
— Pogue (1915), p. 121
His most recommended test, in Pogue's (1915) reprint, was this:
“A third way, which is very much commended for this purpose: dissolve calx in water,then anoint the superficies of the gemm with it, or put a little of this dissolved calx upon the superficies, and if upon this the calx receive a tincture or colour from the gemm, this will shew that gemm to be a very excellent turcuoys.”
— Pogue (1915), p. 121
On glass imitations, Pogue wrote in 1915:
“Invariably, however, they have a vitreous luster, are slightly harder than turquois, and differ from it in specific gravity. The margin is usually minutely splintered from the grinding, and the small broken surfaces are seen with the hand lens to have a conchoidal or shell-like shape, characteristic of glass.”
— Pogue (1915), p. 131
Pogue (1915) added that glass stones
“are apt to contain air bubbles or faint wavy flow lines, indicating that the mass was once molten”
— Pogue (1915), p. 131
Even in 1915, Pogue warned that the best pressed imitation was hard to catch:
“The manufactured product, which is in reality a synthetic turquois, can not in all cases be surely distinguished from the natural mineral by mere examination or by the ordinary tests, for it closely approximates the latter in color, texture, hardness, specific gravity, and chemical composition; and even limonite inclosures in some instances are added to simulate matrix.”
— Pogue (1915), p. 131
Pogue (1915) dated their arrival:
“During the last quarter of the nineteenth century turquoises fabricated in the manner described have come upon the market in considerable numbers, particularly in Europe.”
— Pogue (1915), p. 132
For dyed turquoise, Pogue (1915) gave a light test:
“By artificial light the color of stained turquois is gray-blue and unlike pure turquois appears duller instead of brighter.”
— Pogue (1915), p. 133
From the Library: Branson, Turquoise: The Gem of the Centuries (1975)
1975 primary source. Anything described as current here describes 1975, not today.
Branson's 1975 position on selling treated stone was about disclosure, not the treatment itself:
“The treating of turquoise is not to be condemned and it is not wrong to buy or sell it; but it is wrong to misrepresent it or to mislead people.”
— Branson (1975), p. 61
On the vocabulary, Branson (1975) was just as direct:
“The words treated and stabilized are synonymous.”
— Branson (1975), p. 61
According to Branson (1975, p. 61), soaking soft turquoise to deepen its colour was not new when plastic arrived: it had been done with animal fat and tallow thousands of years earlier, with the same effect but without plastic's permanence.
As of 1975, Branson estimated the share of mined turquoise that goes to treatment:
“Treated turquoise is produced with the inferior and unusable, if not treated, portion of the turquoise that is mined. This is possibly 80 percent of all turquoise mined.”
— Branson (1975), p. 61
On backed stones, Branson (1975) explained why thin turquoise gets an epoxy back:
“Thin pieces of fine turquoise too thin to be cut alone are backed with an epoxy cement mixture which strengthens the stone and makes it much less likely to break”
— Branson (1975), p. 4
Branson (1975) pictured chrysocolla, malachite and variscite as look-alikes and warned:
“These and many other kinds of minerals are frequently mistaken for, and sometimes sold as turquoise.”
— Branson (1975), p. 6
According to Branson (1975, p. 6), natural stones may carry pyrite or open surface cavities, while some cut stones had their cavities filled with metal-loaded epoxy, which is a fill a buyer should ask about.
Branson (1975) treated the knife as a practical check on treated stone:
“can be easily scratched with a hard knife blade”
— Branson (1975), p. 8
According to Branson (1975, p. 8), high-quality turquoise could not be scratched with a knife, and none of the 36 stones on his pages 30-31 could be, while every treated stone he pictured scratched easily.
On whether treatment makes a stone harder, Branson (1975) was blunt:
“It cannot be harder than the plastic.”
— Branson (1975), p. 8
Branson (1975) described the block imitations of his day:
“They are soft enough to be easily scratched with a knife blade.”
— Branson (1975), p. 9
According to Branson (1975, p. 9), plastic imitations were sometimes set in real Indian-made silver; three such pieces had been pawned to a trader in Gallup as genuine turquoise.
According to Branson (1975, p. 9), dyed quartzite and dyed howlite were cut first and dyed afterwards.
On the synthetic sold in 1975 as Luroc, Branson (1975) reported:
“Synthetic turquoise known as "Luroc" is reportedly the same chemical composition as natural turquoise”
— Branson (1975), p. 9
On the glass "Hubbell" beads, Branson (1975) noted the name was looser than the story:
“This type is often called "Hubbell" beads, although many reservation traders had them.”
— Branson (1975), p. 9
He added that the glass did not fool its wearers (Branson, 1975):
“The Navajos valued them highly but knew at a glance they were not their beloved turquoise.”
— Branson (1975), p. 9
From the Library: Chambless & Ryan, Turquoise in America, Part One (2021)
2021 primary source. Anything described as current here describes 2021, not today.
According to Chambless & Ryan (2021, p. 175), at least 80 percent of turquoise is too soft or chalky to cut for jewelry without treatment, and even among the untreated 20 percent perhaps only the top 5 percent was considered high-grade. [3]
Chambless & Ryan (2021) date the modern era of treated stone:
“From the 1950s on, this and other treatments to improve color and hardness have allowed the use of turquoise that previously was too soft or lacked enough color to be used in commercial jewelry production.”
— Chambless & Ryan (2021), p. 182 [3]
According to Chambless & Ryan (2021, p. 183), a second technique that followed epoxy resin was backing: applying the strengthening agent to the back of the cut cabochon instead of infusing the rough stone; it gained popularity in the late 1960s. [3]
Chambless & Ryan (2021) explain why a backed stone can still be natural:
“The external backing provides strength to the stone but can be removed, allowing the turquoise to remain natural and untreated while reducing the chance of fracture.”
— Chambless & Ryan (2021), p. 183 [3]
Chambless & Ryan (2021), summarizing a 1939 report on Colorado's King mines, record a buyer belief worth knowing:
“Interestingly, the reason stated for the demand from the tourist trade for more matrix in the turquoise was they believed the matrix was a guarantee of the stone's "genuineness."”
— Chambless & Ryan (2021), p. 190 [3]
From the Library: Lowry, Turquoise: The World Story of a Fascinating Gemstone (2010)
2010 primary source. Anything described as current here describes 2010, not today.
On the hot-pin test, Lowry (2010) is brief:
“This test is accurate for cheap plastic knockoffs, but it is ineffective in identifying most other imitations.”
— Lowry (2010), p. 116 [4]
On judging a stone by eye, Lowry (2010) notes the limits:
“There are over 500 deposits of turquoise in the world. There are only so many color and matrix combinations available for the eye to catalog or for nature to produce.”
— Lowry (2010), p. 116 [4]
On shine, Lowry (2010) writes:
“A high polish does not necessarily determine whether a turquoise is natural or not. A dull waxy surface is a better guide that a stone might not be natural.”
— Lowry (2010), p. 117 [4]
And on the word 'pawn,' Lowry (2010):
“The term pawn does not designate whether the turquoise stones are natural, treated, plastic, glass, or some other imitation.”
— Lowry (2010), p. 117 [4]
According to Lowry (2010, p. 118), grinding the surface until the heat gives off a plastic smell is one of the better tests for stone injected with plastics or waxes, but it will not catch oiled, enhanced or many other imitations. [4]
According to Lowry (2010, p. 119), variscite, a hydrated aluminum phosphate and a separate mineral, has been marketed under the term "variquoise," and white stones such as magnesite and dolomite have also been sold in the turquoise trade. [4]
Lowry (2010) describes a matrix treatment that leaves the turquoise itself untouched:
“Since a darker-colored matrix is more popular in the turquoise markets, black or brown shoe polish or other dyes are used to darken the matrix in the rough and/or finished cabochons.”
— Lowry (2010), p. 169 [4]
According to Lowry (2010, p. 169), as of 2010 lapidaries had dyed the matrix of stone from mines such as Sleeping Beauty and Kingman, which mostly have a natural white matrix, plus small percentages of Lone Mountain and Nacozari; because the turquoise color itself was unchanged, most American dealers then accepted the practice. [4]
According to Lowry (2010, p. 169), lapidaries also fill surface pits with crushed rock or grit mixed with glue, and both pit filling and matrix dyeing should be disclosed to the buyer. [4]
On backing, Lowry (2010) gives an earlier start date than the one cited above:
“Backing turquoise is generally an American concept started in the 1950s for several reasons:”
— Lowry (2010), p. 167 [4]
According to Lowry (2010, p. 167), backing lets thin veins be set, gives the stone a flat bottom and raises the carat yield per pound; he adds that doublet-cut stones should be identified to consumers and that a buyer should make sure a stone does not carry an undue amount of backing. [4]
According to Lowry (2010, p. 194), U.S. Federal Trade Commission guidelines suggest a written guarantee that gives the seller's name, address, phone number and date and describes the grade, source and condition of the stone. [4]
According to Lowry (2010, p. 195), only about 15 percent of the world's turquoise production is hard enough to grind, shape and polish (Mohs 4.5-6.5); on average the other 85 percent is too soft to shape or carve and will not take a high polish without falling apart or burning. [4] Lowry (2002, pp. 34, 38) also puts the gem-grade share at about 15 percent and notes that the lowest grade is soft enough to write with on a chalkboard. [11]
On stabilization, Lowry (2010) drew a firm line:
“Stabilized turquoise is not natural turquoise.”
— Lowry (2010), p. 203 [4]
According to Lowry (2010, p. 203), "clear shot" stabilization uses clear resins with no added dyes, while "color shot" stabilization adds a dye or pigment for extra color and is less stable, because the dyes may break down over time with heat, foreign substances and wear. Lowry adds that even clear-shot stone does not end up the same color as the original chalk, because the resin changes how light passes through it. [4]
On how plastic imitations fake a matrix, Lowry (2010) wrote:
“There are plastics that are mixed with colored rock or pyrites so that the matrix has the appearance of a "natural" formation.”
— Lowry (2010), p. 207 [4]
According to Lowry (2010, p. 209), the Gilson synthetic of the 1970s reproduced the clarity and robin's-egg blue of Persian turquoise, was sold worldwide, and was later made with an added black matrix. [4]
According to Lowry (2010, p. 209), the best-known glass imitations in the Southwest were the "Hubbell" beads, named for the Hubbell Trading Post near Ganado, Arizona, which traded them to artisans across the region. [4]
Lowry (2010) put the buyer's remedy plainly:
“If the consumer wants to buy a turquoise from a Classic Mine, then he or she needs to get a written guarantee of the mine source from the miner and salesperson.”
— Lowry (2010), p. 231 [4]
From the Library: Laufer, Notes on Turquois in the East (1913)
1913 primary source. Anything described as current here describes 1913, not today.
Laufer (1913) quoted Watt's Dictionary of the Economic Products of India on reported Indian turquoise:
“but, according to Ball, the so-called turquoises of Ajmir are only blue copper ore.”
— Laufer (1913), p. 4 [5]
Laufer (1913) described greenish Tibetan stones that Chinese traders called imitations:
“I was first inclined to accept the opinion of the Chinese consulted by me, and to regard these stones as imitations, but Dr. Joseph E. Pogue to whom I sent three specimens for examination convinced me that this opinion was unfounded.”
— Laufer (1913), p. 18 [5]
Pogue's report on the three stones, as Laufer (1913) printed it:
“All three specimens are phosphates, giving good tests. Washed with strong ammonia, they did not lose their color, as most artificially colored turquoises will do when so treated.”
— Laufer (1913), p. 18 [5]
From the Library: Kunz, Gems and Precious Stones of North America (1890)
1890 primary source. Anything described as current here describes 1890, not today.
As of 1890, Kunz (1890, p. 59) gave this test for Prussian-blue stain: wash the stone in alcohol, wipe it, and lay it briefly in ammonia, when a stained stone's blue partly or wholly disappears and it returns to its natural greenish hue; to keep the face intact, he built a wax dam on the face and put ammonia only on the back, where a stained stone showed a difference in shade at once. [6]
According to Kunz (1890, p. 59), the stain was only superficial and could be scraped off the back with a knife without harming the stone. [6]
From the Library: Frank, Indian Silver Jewelry of the Southwest (1990)
1990 primary source. Anything described as current here describes 1990, not today.
According to Frank (1990, p. 118, Fig. 140), cut blue glass stood in for stone on some early pieces: one bracelet of about 1920 had twelve hexagonal glass pieces soldered onto four strands of twisted wire, and glass was occasionally used for necklace beads or set in bracelets and rings. [7]
From the Library: Turnbaugh, Indian Jewelry of the American Southwest (2007)
2007 primary source. Anything described as current here describes 2007, not today.
Writing in the late 1980s, Turnbaugh (2007, p. 33) described three tests then in use. In the hot-needle test, a stone that only charred was probably natural, while one that charred and melted was stabilized or not genuine. In the knife-scratch test, ragged scratch edges under magnification suggested real stone and smooth edges a stabilized one. Under ultraviolet light, plasticized turquoise often fluoresced. [8]
Even so, the Turnbaughs (2007) did not rely on these tests in practice:
“Naturally, it is impractical to perform most of these tests before purchasing an item, so the best advice is to deal with someone who is trustworthy when buying Indian jewelry.”
— Turnbaugh (2007), p. 33 [8]
According to Turnbaugh (2007, p. 33), other stones, including jade, variscite, chrysocolla, malachite, dyed howlite and odontolite, blue sodalite and lapis lazuli, as well as reconstituted or block turquoise, could be used instead of natural turquoise. [8]
From the Library: Ryan & Chambless, Turquoise in America Part Two: 1910–1990 (2020)
2020 primary source. Anything described as current here describes 2020, not today.
According to Ryan & Chambless (2020, p. 58), turquoise runs 5-6 on the Mohs scale, the most desirable gem grade makes up only about 0.1% of all turquoise mined, and estimates put only about 5-20% of turquoise hard enough to be cut and polished for jewelry without treatment to harden it or change its color, a share that at many mines could be much lower. [9]
Nevada miners Grace and John Callahan, in a 1948 Desert Magazine interview reprinted by Ryan & Chambless (2020), on oiled stone:
“We find lots we could oil up and make look pretty but it hurt our own business to put inferior turquoise on the market. During the war when turquoise became so popular, some sellers cashed in by doctoring poor stones.”
— Ryan & Chambless (2020), p. 139 [9]
The Callahans went on to explain why buyers had grown wary, as reprinted by Ryan & Chambless (2020):
“They don't want to pay a lot of money then have a pretty blue stone turn a greasy green.”
— Ryan & Chambless (2020), p. 139 [9]
According to Ryan & Chambless (2020, p. 170), in the 1976 International Turquoise Annual, Arizona Mineral Museum director Lee Hammons proposed a standard practice of disclosing whether a stone was natural or treated in any way, its mine or district, its weight, and the identity of the jewelry maker; a grading method followed in 1977, and both efforts were largely ignored. [9]
Recollections below are the speakers' own memories, recorded in interviews published by Ryan & Chambless (2020); they are credited to the speaker, not stated as fact.
D. Robert Smith recalled, in an interview published by Ryan & Chambless (2020, p. 201), that in the 1970s treated material might sell for two dollars a carat while completely natural stone sold for five to seven dollars a carat. [9]
D. Robert Smith, in an interview published by Ryan & Chambless (2020), on where the line sits:
“Some purists think if you put backing on it or if you put Zam on it or any kind of polish, you don't have a natural stone anymore.”
— Ryan & Chambless (2020), p. 201 [9]
Bruce Woods recalled, in an interview published by Ryan & Chambless (2020, p. 193), that chalk sent to Hardy in Kingman for treatment came back as nice web rock that could undersell natural stone, and that once his crew saw it they never sold chalk again. [9]
According to Ryan & Chambless (2020, p. 217), thin vein turquoise too delicate to cut was treated as waste for many years, until in 1969 Bill King found how to back it with Devcon so it could be cut and used in jewelry. [9]
Bill King recalled the effect, in an interview published by Ryan & Chambless (2020):
“Everybody got into backing turquoise. Pretty quick, you couldn't buy that thin stuff.”
— Ryan & Chambless (2020), p. 218 [9]
Doug Magnus recalled, in an interview published by Ryan & Chambless (2020, p. 268), that as Chinese turquoise spread vendors rarely disclosed treatments; Colbaugh-process stabilized Kingman, a clear acrylic, gave off a distinct plastic smell on the grinding wheel, but some Chinese material changed color when reshaped and gave off an unusual rubbery or other smell, so a cutter could not tell what treatment it carried. [9]
According to Ryan & Chambless (2020, p. 277), turquoise has been treated in some way to improve its colour, hardness or both ever since it was first mined in Egypt, because it is a relatively soft stone, about 5 to 6 on the Mohs scale. [9]
According to Ryan & Chambless (2020, p. 277), only higher-grade turquoise can be used in jewelry without treatment and is called natural; depending on the mine it may be as little as 2% to 3% of production, with gem grade as little as 0.1%, and only in exceptional mines 15% to 20% or more. [9]
According to Ryan & Chambless (2020, p. 278), before plastic polymers most turquoise was treated with surface oil or wax; the 1970s boom brought stabilized turquoise, in which a plastic polymer is introduced into the stone to harden it and deepen and hold the colour, and a separate process that introduces silica to make enhanced turquoise. [9]
Ryan & Chambless (2020) on why disclosure matters:
“The uninformed consumer has little means to discriminate between treated or natural without full transparency and disclosure in the marketplace.”
— Ryan & Chambless (2020), p. 278 [9]
According to Ryan & Chambless (2020, p. 279), in 1969 Bill King developed backing thin, fragile vein turquoise with Devcon and similar epoxy-steel products so it could be used in jewelry; because backing sits only on the surface and can be removed, most in the trade do not count backed natural turquoise as treated. [9]
According to Ryan & Chambless (2020, p. 279), surface treatments are also used to fill pits in soft matrix and to mitigate cracks from blasting in copper mines; some accept this as leaving the stone natural and others disagree, and the authors' rule is that any treatment is welcome as long as it is fully disclosed. [9]
Mike Ryan II, introducing the turquoise gallery in Ryan & Chambless (2020), on how sure anyone can be of a mine attribution:
“Turquoise identification is always a challenge. It is difficult to be certain unless one has mined the stone themselves, purchased from the miner who mined the stone or purchased from a reputable dealer who received the stone from the miner.”
— Ryan & Chambless (2020), p. 285 [9]
According to Ryan & Chambless (2020, p. 285), where a stone could not be traced that way, especially turquoise already set in jewelry, they qualified the attribution with the word 'probable', meaning more likely than not that the turquoise is what it is identified as. [9]
Richard M. Shull, G.G., in an appendix to Ryan & Chambless (2020), on why so much turquoise is imitated or treated:
“Whereas turquoise appears to be an abundant mineral, true gem-grade turquoise is rare.”
— Ryan & Chambless (2020), p. 339 [9]
Richard M. Shull, in an appendix to Ryan & Chambless (2020, p. 339), listed the imitations as plastic, glass and dyed or stabilized magnesite or howlite. He described magnesite and howlite as common white minerals that can have matrix patterns similar to turquoise and are porous enough to take dye easily, and wrote that unscrupulous dealers often sell them cheaply as real turquoise. [9]
Richard M. Shull, in an appendix to Ryan & Chambless (2020, p. 339), called the hot-pin test somewhat reliable for detecting resin stabilization: a red-hot pin placed against the stone gives off an acrid odor if it is stabilized. He cautioned that because magnesite can also be resin-treated, the test confirms only the treatment, not what the base stone is. [9]
According to Richard M. Shull, in an appendix to Ryan & Chambless (2020, p. 339), electrically treated turquoise is virtually impossible to detect outside a laboratory. [9]
Richard M. Shull, in an appendix to Ryan & Chambless (2020, p. 338), warned that variscite forms in the same kind of geology as turquoise and can closely resemble the greener stones. High-silica variscite reaches the same 5-6 hardness and takes the same polish. Even so, the two are separate mineral groups that do not blend into one another. [9]
From the Library: Khazeni, Sky Blue Stone (2014)
2014 primary source. Anything described as current here describes 2014, not today.
According to Khazeni (2014, p. 41), most Persian turquoise that reached the world market was set in rings strung together on a cord; some European lapidary manuals said this let buyers test many stones at once, by seeing whether they lost their colour when tucked under an armpit. [10]
From the Library: Lowry, Turquoise Unearthed: An Illustrated Guide (2002)
2002 primary source. Anything described as current here describes 2002, not today.
Writing in 2002, Lowry (2002) put it plainly:
“Most turquoise marketed today has been treated”
— Lowry (2002), p. 34 [11]
Lowry (2002) listed what else a dealer should disclose:
“Dealers should also inform the buyer if a stone's matrix has been dyed, if pits have been filled and smoothed, if it is doublet cut, or if it has been sawed with an oil-based compound, which could alter the color of the turquoise.”
— Lowry (2002), p. 38 [11]
Lowry (2002) on imitations:
“Real minerals, such as howlite and quartzite, are sometimes dyed to imitate natural turquoise and can be hard to detect as fake.”
— Lowry (2002), p. 41 [11]
Lowry (2002) on what to ask for:
“For example, if the seller tells you that the turquoise jewelry you're buying is sterling silver and natural turquoise, and was handmade by a Native American artisan, you should ask that this information be spelled out on your receipt.”
— Lowry (2002), p. 41 [11]
Lowry (2002) added:
“A reputable dealer will not hesitate to give you a detailed written confirmation.”
— Lowry (2002), p. 41 [11]
From the Library: Adair, The Navajo and Pueblo Silversmiths (1944)
1944 primary source. Anything described as current here describes 1944, not today.
Mary Burnsides, a Navajo woman smith, told Adair of turquoise-colored glass beads she bought in Gallup and set in silver, as Adair (1944) recorded:
“The Navajo knew that these weren't turquoise, but they thought that they looked pretty so they bought lots of them.”
— Adair (1944), p. 88 [12]
According to Adair (1944, p. 88), these may have been frosted glass beads of a turquoise color made in Czechoslovakia, large lots of which had been sold in the Southwest some years before. [12]
Adair (1944) added:
“Contrary to the opinions of many people, the Navajo are never fooled by fake turquoise.”
— Adair (1944), p. 88 [12]
According to Adair (1944, p. 199), the stone the Navajo and Zuni preferred above all others around 1940 was a clear, deep robin's-egg blue, which the Navajo called "male" turquoise; the less rare greenish stone they called "female" turquoise, and they valued stones of even color with none of the matrix showing. [12]
Writing in 1944, Adair described how cheaper turquoise had been colored for the Southwest trade:
“In the past, great quantities of this cheap turquoise have been shipped to Germany, dyed a deeper color, and shipped back to the Southwest to be set in silver by the Indian smiths. Inferior grades of stones are also given a deeper color by soaking them in grease.”
— Adair (1944), p. 200 [12]
Adair (1944) also recorded how such greased stones could give themselves away:
“More than one buyer has been surprised to find that stones left accidentally in the sun have become greasy, because the grease has sweated out of the stones.”
— Adair (1944), p. 200 [12]
Synthetic turquoise was already a concern when Adair wrote in 1944:
“Turquoise may also be produced synthetically in a laboratory, even to the extent of having a simulated veining of matrix.”
— Adair (1944), p. 200 [12]
On color that does not last, Adair (1944) wrote:
“The best turquoise of deep blue retains its color, while the softer stones of a lighter blue and of a greenish cast eventually become a dull and unattractive green.”
— Adair (1944), p. 200 [12]
Adair's 1944 advice to a new buyer:
“The buyer learns to distinguish good from poor or imitation turquoise only with experience, after having seen and handled many pieces. The best assurance of quality, for the novice, is in buying from reputable dealers who will guarantee the quality of the stones.”
— Adair (1944), p. 200 [12]
From the Library: Baxter, Encyclopedia of Native American Jewelry (2000)
2000 primary source. Anything described as current here describes 2000, not today.
Writing in 2000, Baxter noted one tell that buyers of her day relied on:
“Generally, fake turquoise feels denser and heavier than the real stone.”
— Baxter (2000), p. 76 [13]
Baxter (2000) also named the most promising laboratory method of her time:
“A technique developed in the 1980s using near-infrared spectroscopy is most promising in detecting imitation turquoise.”
— Baxter (2000), p. 76 [13]
Baxter (2000) set out the disclosure rule as it stood:
“Good business practice and ethics (including the regulations of the Indian Arts and Crafts Association [IACA]) require that the artist using this treatment on stones, or dealers selling the piece, represent the material as having been treated.”
— Baxter (2000), p. 166 [13]
She was frank about the buyer's position (Baxter, 2000):
“The consumer is often at the mercy of the seller, and that individual’s honesty in portraying the materials used for a piece of jewelry.”
— Baxter (2000), p. 167 [13]
According to Baxter (2000, p. 167), stabilizing was regarded with some suspicion because it had so easily been ignored or misrepresented. [13]
As of 2000, Baxter (2000) wrote:
“Lapidarists look for four key factors in determining turquoise quality: color, carat weight, cut, and matrix clarity. Top-grade turquoise material, as defined by the industry, amounts to only around 10 percent of the turquoise on the market.”
— Baxter (2000), p. 183 [13]
Baxter (2000, p. 183) distinguished reconstructed turquoise, made by artificially bonding small pieces of natural turquoise, from reconstituted turquoise, made by pulverizing low-grade turquoise and mixing the powder with a colored resin or other hardening substance. [13]
From the Library: Woodward, A Brief History of Navajo Silversmithing (1946)
1946 primary source. Anything described as current here describes 1946, not today.
Writing in 1938, Woodward (1946) described how low-grade stone was greened:
“if the turquoise is boiled for two or three hours in mutton tallow, bacon drippings, lubricating oil, or paraffine, a variety of greenish tints are imparted to the soft matrix, giving the stones the appearance of having been worn some time.”
— Woodward (1946), p. 47 [14]
The test he described in 1938, Woodward (1946):
“One can detect the oil dyed stones by either smelling them or holding them in the hand for a few moments.”
— Woodward (1946), p. 47 [14]
For a brown matrix, as of 1938, Woodward (1946) reported:
“Occasionally when a brown matrix is desired by the turquoise dyer he resorts to the use of a small brush and a bottle of iodine.”
— Woodward (1946), p. 48 [14]
According to Woodward (1946, p. 47), the cutting of small stones abroad was then done chiefly in Oberstein, Germany, where poor-grade turquoise was cut, dyed, polished and sent back to the United States. [14]
Field Notes by Mateo James
This page puts the too-soft share at 85 percent, while Branson's 1975 note says treated stone comes from possibly 80 percent of all turquoise mined. The figures are close but not the same, so I have shown both.
Our table calls the scratch test folklore, and Branson, writing in 1975, used the knife as his working check for treated stone. The two readings disagree, and I have left both on the page rather than pick one quietly. Where Chambless and Ryan cover a point, their account leads for us; on this test the part of their work we hold is silent, so it stays an open disagreement.
I notice Lowry (2010) dates backing to the 1950s, while Chambless & Ryan (2021) say it gained popularity in the late 1960s. I've left both on the page. I tend to side with Chambless & Ryan.
Our page says no dye goes into stabilized turquoise. Lowry (2010) splits stabilization into clear-shot, which uses no dye, and color-shot, which adds dye or pigment, and he describes the first stabilizing experiments as using blue dye. Branson's 1975 plate describes undyed material, so both kinds existed in the trade. I have shown both here rather than choose one.
Field Notes by Mateo James: Our page calls the scratch test folklore, while the Turnbaughs, writing in the late 1980s, described a knife-scratch test alongside hot-needle and ultraviolet checks. They also wrote that most of these tests were impractical before buying and that the best advice was to deal with someone trustworthy, which is close to where our page ends up. I record the difference rather than resolve it.
Our table of home tests says the hot pin works only on cheap plastic. Richard Shull, a graduate gemologist writing in the Part Two appendix, calls it a somewhat reliable test for resin stabilization. He adds that it tells you only that the stone was treated, not what the stone is. Those two verdicts do not match, and I am noting the disagreement here rather than settling it.
How we use these words. At T.Skies we sort turquoise into three groups. Natural turquoise is as it comes out of the earth, with nothing added except the water or mineral oil used while cutting. Treated turquoise has something added, and we label it stabilized (clear resin that locks in the stone's own color and integrity), enhanced (dyed, hardened, or both), or stabilized enhanced. Upcycled and manufactured material (composite, chip inlay, reconstituted, block) is made from turquoise pieces or powder bound together, and it is its own category. A source interviewed in Chambless & Ryan (2020, p. 281) says stabilizing can deepen the color “five to ten times”; our Stabilized label means clear resin only, with no dye and no separate hardening process such as Zachery. Whatever the label, a treated stone should be disclosed as treated: the FTC Jewelry Guides (16 CFR §23.24) require it whenever a treatment isn't permanent, needs special care, or significantly affects the stone's value.
Sources
- Joe Dan Lowry & Joe P. Lowry, Turquoise: The World Story of a Fascinating Gemstone (2010) — formation, hardness, treatments, testing, grading.
- Oscar T. Branson, Turquoise: The Gem of the Centuries (1975) — stabilization process and economics.
- U.S. Federal Trade Commission, Guides for the Jewelry, Precious Metals, and Pewter Industries, 16 CFR Part 23 (§§23.1, 23.24, 23.27).
- Gemological Institute of America — gia.edu.
- Branson, Oscar T. Turquoise: The Gem of the Centuries. Santa Fe: Treasure Chest Publications, 1975. Cited by printed page. Statements describe conditions as of 1975.
- Pogue, Joseph E. The Turquois: A Study of Its History, Mineralogy, Geology, Ethnology, Archaeology, Mythology, Folklore, and Technology. Memoirs of the National Academy of Sciences, Vol. XII, Part II, Third Memoir. Washington, 1915. Public domain. Cited by printed page. Statements describe conditions as of 1915.
- Chambless, Philip, and Mike Ryan II. Turquoise in America, Part One: The Great American Turquoise Rush, 1890–1910. Revised first edition. Callais Press, 2021. Cited by printed page. Statements describe conditions as of 2021.
- Lowry, Joe Dan, and Joe P. Lowry. Turquoise: The World Story of a Fascinating Gemstone. Layton, UT: Gibbs Smith, 2010. Cited by printed page. Statements describe conditions as of 2010.
- Laufer, Berthold. Notes on Turquois in the East. Field Museum of Natural History, Anthropological Series, Vol. XIII, No. 1. Chicago, 1913. Public domain. Cited by printed page. Statements describe conditions as of 1913.
- Kunz, George F. Gems and Precious Stones of North America. New York: The Scientific Publishing Company, 1890. Public domain. Cited by printed page. Statements describe conditions as of 1890.
- Frank, Larry, with the assistance of Millard J. Holbrook II. Indian Silver Jewelry of the Southwest, 1868-1930. Atglen, PA: Schiffer Publishing, 1990. First published 1978 by New York Graphic Society. Cited by printed page. Statements describe conditions as of 1990.
- Turnbaugh, William A., and Sarah Peabody Turnbaugh. Indian Jewelry of the American Southwest. Foreword by Barry M. Goldwater. Atglen, PA: Schiffer Publishing, 2007 (copyright 1996 and 2007; first published 1988). ISBN 0-7643-2577-9. Cited by printed page. Statements describe conditions as of 2007.
- Ryan, Mike, II, and Philip Chambless. Turquoise in America, Part Two: 1910–1990. Callais Press, 2020. Cited by printed page. Statements describe conditions as of 2020.
- Khazeni, Arash. Sky Blue Stone: The Turquoise Trade in World History. The California World History Library 20. Berkeley: University of California Press, 2014. Cited by printed page. Statements describe conditions as of 2014.
- Lowry, Joe Dan, and Joe P. Lowry. Turquoise Unearthed: An Illustrated Guide. Photography by Mark Nohl. Tucson, AZ: Rio Nuevo Publishers, 2002. Cited by printed page. Statements describe conditions as of 2002.
- Adair, John. The Navajo and Pueblo Silversmiths. The Civilization of the American Indian Series. Norman: University of Oklahoma Press, 1944. Cited by printed page. Statements describe conditions as of 1944.
- Baxter, Paula A., with Allison Bird-Romero. Encyclopedia of Native American Jewelry: A Guide to History, People, and Terms. Phoenix: Oryx Press, 2000. Cited by printed page. Statements describe conditions as of 2000.
- Woodward, Arthur. A Brief History of Navajo Silversmithing. With field notes by Richard Van Valkenburgh. Museum of Northern Arizona Bulletin 14, 2d ed. Flagstaff: Northern Arizona Society of Science and Art, December 1946 (first edition 1938). Cited by printed page. Statements describe conditions as of 1946.