Turquoise Value, How Much is Turquoise Worth?

What is your turquoise worth? It is one of the most common questions collectors ask, and the honest answer starts with a correction: there is no single price list for turquoise, and no laboratory grade that the whole trade agrees on. Value is built from a handful of qualities you can learn to judge by eye and by asking the right questions. This guide walks through them, gives you the scoring system this page has used since 2014 to put a stone on a scale, and shows how the same qualities decide what you pay for finished turquoise jewelry.

Why turquoise has no single price list

Turquoise grading grew up in different places for different buyers. Joe Dan Lowry and Joe P. Lowry of the Turquoise Museum: “Regional and cultural traditions, marketing, fashion trends, supply, demand, and opinions have continued to influence the turquoise trade’s various grading systems.”

Two of those systems still shape the market. “The most well known tradition of grading turquoise is the Persian system, which defines the best grade as a stone with perfect clarity and the deepest blue color. The American system defines the best grade as a stone that is from one of the most famous and rare mines that has a good blue color and a spiderweb matrix.” Put together, the Lowrys write, “the global turquoise industry has defined the greatest rarities of turquoise as condition, source, color, clarity, and/or matrix.”

Expect two honest experts to disagree. “Just as some turquoise dealers might consider one turquoise mine or color high grade, others might classify it as common or even low grade.” And the Lowrys add the point most price guides leave out: “Many times the consumer just buys what he or she likes and can afford.”

The formula: weight times quality

Turquoise Value = Weight (carats) × Quality

Weight

Loose turquoise is weighed in carats, and five carats make one gram. Weight tells you how much stone you have. Quality tells you what each carat of it is worth, and quality varies far more than weight does. Size also counts on its own, because big pieces are harder to find: “A large rough, cabochon, specimen, or carving of turquoise is rarer and thereby worth more than smaller counterparts from the same mine and/or grade” (Lowry).

Turquoise Quality Index

The Turquoise Quality Index (TQI) is a 100-point scoring guide created by Mateo James and first published on this page in 2014. It is not an industry or laboratory standard, and as you have just read, the trade doesn't have one. What the TQI does is put the factors the experts name into an order and give each one a weight, so you can score a stone the same way every time. The higher the score, the higher the grade.

High scores are rare because most turquoise never reaches the market as natural stone. The Indian Arts and Crafts Board (IACB): “When retrieved from the earth, approximately 85% of the turquoise is too soft to cut or polish,” and “Approximately 15% of the world’s turquoise supply is natural turquoise.”

How to Find TQI

The TQI splits a stone’s value into two parts: its physical structure (55 points) and its rarity (45 points). Each part is broken into indicators, eight in all. Score each one from the charts below and add them up. Some indicators are easy to agree on. Color and matrix are the ones where experts argue, so treat your score as an informed estimate, not a certificate. For an expensive stone, ask a specialist.

What turquoise is matters to every score. Chemically, Joseph Pogue wrote in 1915, “it is a phosphate of aluminum carrying small quantities of copper and iron, to which its color is due.” The copper and iron make the color. The host rock, left in the stone, makes the matrix.

Measuring Stone Hardness

Harder turquoise takes a better polish, wears better and is worth more. Softness is the rule, not the exception. Philip Chambless and Mike Ryan II: “It is estimated that up to 80 percent of all turquoise produced is too soft and pale to be used commercially unless it is treated for color or hardness or both.” The softest is chalk. The IACB: “White turquoise, referred to as ‘chalk,’ is generally too soft to cut or polish and is not typically graded as a gemstone.”

Don't scratch-test a stone you care about. It damages the stone you are trying to measure. Judge by eye and by hand instead. A dull, chalky natural stone scores 10. A professionally stabilized stone can score up to 15, never more, however hard the resin made it. Only naturally hard stone earns 20. If you can't tell, give it 15.

Enhanced Turquoise Properties

This is the most important score on the sheet, which is why it carries 20 points. The Lowrys: “Determining the condition of a turquoise stone, carving, or specimen is the most important factor in beginning to determine a turquoise’s grade and value.” The rule underneath it: “A turquoise that is natural is more rare than any comparable turquoise that has been treated.”

Treatment is not fraud. Undisclosed treatment is. Here are the levels, from least to most valuable:

• Imitation (1). Plastic or glass, not turquoise at all.
• Block or reconstituted (2–5). The IACB defines block turquoise this way: “chips and fragments are mixed with epoxy to form blocks for cutting.”
• Dyed or heavily treated (6–12). Dyed means “a pigment is added to deepen the stone’s color or create a ‘matrix’ design within a treated stone” (IACB). The Lowrys warn that when dye is added to stabilizing, “the color is susceptible to breaking down over time due to direct sunlight or changing temperatures.”
• Professionally stabilized, oiled or waxed (13–19). Stabilized is “turquoise combined with colorless resins (plastics) under a vacuum or pressure to harden the stone and darken the color” (IACB). Done well, “the increased colors from the whitish colors are generally permanent” (Lowry). Oil and wax are gentler but less stable: those stones “are susceptible to a slow loss or change of color” (Lowry), so score them toward the bottom of this band.
• Natural (20). Nothing done to it but cutting and polishing.
• Raw chalk (5). Natural, but it can't be used without treatment, so it can't score as natural.

How treatments are named and disclosed, and how to spot the fakes, is its own guide: fake and treated turquoise, explained.

Turquoise Stone Composition

Composition asks what the stone is made of: how much is sound turquoise, and how sound is the rock around it. The Lowrys describe the host rock “that the turquoise formed in, on, and around” as generally part of the formation. Grainy, powdery turquoise and crumbly host rock score low, because they need stabilizing just to be usable. Solid natural turquoise, whether clean or with a solid, tight matrix, scores high. Whether a clean stone or a matrix stone is better is a regional argument, as the Persian and American systems show. The TQI's top score goes to rare inclusions that add depth without weakening the stone, such as pyrite. The Lowrys single out the Morenci Mine in Arizona as “famous for a nice blue color and pyrites in its matrix formation.”

Cut

Cutting adds a small amount of value: it costs time and skill, and it shows what a stone really is. Rough turquoise, straight from the ground, is hard to judge until it is cut. Rough scores 1. Tumbled or roughly cut stone scores 2. A standard machine-cut cabochon scores 3, a hand-shaped cabochon 4, and a stone sculpted by an artist 5.

Turquoise Availability

This score is about the mine, and it carries 20 points for a reason. The Lowrys: “The most influential rarity of a turquoise’s value is where a specific turquoise was mined.” And: “Turquoise collected from the classic mines is generally more valuable than turquoise from lesser-known mines that may produce a similar color and matrix.”

A mine name alone isn't enough, though. The stone has to look like the mine's best: “A turquoise stone with a classic color and/or matrix that matches a Classic Mine is generally worth more money than a turquoise stone from the same mine that does not have the marketed Classic look of that mine.”

Mines producing large amounts score in the middle. Kingman is the example: Chambless and Ryan call Colbaugh Processing, which holds the Kingman concession, “the largest turquoise producer in the United States” (more in Kingman vs. Sleeping Beauty turquoise). Smaller mines score higher. At the top are the tiny producers the trade calls hat mines: “Some mines are large and productive while other mines are small enough that their whole production output might fit in a hat (aka a hat mine).” Lander Blue in Nevada, discovered in 1973, is the famous case. It “became famous for its limited production (estimated at 108 pounds rough) and its quality grade of color and spiderweb matrix.” Every Southwest source is on one map at the turquoise mines of the Southwest.

A correction to this page. Earlier versions gave the top score to “fossil turquoise” formed from sea shells. That was wrong. The Lowrys describe the stones sold as fossil turquoise as concretions: “an outside turquoise formation occurring over an inside formation made up of a mixture of iron oxide, hyalophane, quartz, and mica. Though not actually a fossil,” they are a geological rarity. Real fossil bone stained blue is something else again. Pogue calls it “odontolite, or bone turquois, which, resembling somewhat inferior turquois, has been constantly confounded with the real mineral.” It is not turquoise. The top score now goes to extremely rare natural formations.

Color

Color is the most argued-over score. The IACB settles the blue-versus-green debate plainly: “Natural blue and green turquoise stones are the most sought after and have many color variations. However, neither of these two colors is more valuable than the other.” What matters is how deep and clear the color is: “The higher grade turquoise has greater clarity and deeper color.”

The Lowrys add a practical rule: “The darkest colors are the rarest to find and therefore have a greater value than lighter colors. It is important to compare blue colors of turquoise to other blues and green colors of turquoise to other green colors.” Blue is generally more sought after, they note, “but there are several famous mines that produce green turquoise and are very collectible in their own right.” So the TQI scores the depth and purity of a color, not its hue. For the full picture, see how turquoise color is graded.

Matrix Pattern

Matrix is the host rock left in the stone. The IACB: “If a matrix is present, it will appear as tiny veins or dots of other rock within the turquoise, which can be golden, brown, black, white, or sienna in color. An evenly distributed matrix is desired.” The Lowrys grade it by pattern. Low-grade matrix is “when the host rock dominates the turquoise stone.” Spiderweb is “the rarest matrix; these formations occur when the host rock forms an evenly placed pattern within the turquoise formation.”

No matrix is not a warning sign. Some buyer's guides say a stone without matrix is probably fake. The Persian system prizes exactly that stone, and clean clarity is hard to find. The Lowrys: “When purchasing a stone for clarity, always check the bottom of the stone to see if there is any host rock underneath. A cabochon that has complete clarity is more rare than a cabochon that has a surface clarity but the bottom of the cab has matrix.” A perfectly clean stone and a fine spiderweb both earn 8–9. An exceptional natural pattern earns 10.

Be careful with dark, dramatic webbing on a cheap stone. The IACB’s definition of dyed turquoise includes pigment added to “create a ‘matrix’ design.” To check a stone before you buy it, see how to tell if turquoise is real.

Size That Matters

Size is easy to measure and a small factor in price. A single large piece is worth a little more per carat than several small pieces of the same total weight, because large, unbroken turquoise is harder to find. Measure the stone at its widest point.

Turquoise Value: From TQI Score to Price

Add your eight scores together and find the grade in the table above. This page used to turn that score into a dollar figure per carat. We have taken that chart down. Turquoise prices move with supply and demand, and a printed price table goes out of date without telling you. How price relates to grade doesn't change:

• Rarity sets the price. The Lowrys: “A turquoise’s rarity and thereby its value is relative to how it obtained its pretty color and usability.”
• Natural beats treated, mine for mine. They list it as a rule: “A natural Kingman turquoise nugget necklace is rarer and more valuable than a Kingman nugget necklace that is treated to look like it.”
• Treated stone still has grades. “Stabilized, enhanced or other treated stones are generally graded according to their turquoise mine source, color, matrix, and clarity, which is similar to grading natural turquoise.” Imitations are graded too, “according to the kind of imitation and how it is being used in art and then marketed to the public.”
• A price that seems too low probably is. The IACB: “Realize that authentic handmade pieces may be expensive…if a price seems too good to be true, be sure to ask more questions about the item and its maker.”

Beyond the stone: what sets the price of turquoise jewelry

A stone's grade is one part of a jewelry price. Three other things count as much when you buy a finished ring, turquoise necklace or pair of turquoise earrings.

The silver

“Sterling” is a regulated word. Under the Federal Trade Commission’s Jewelry Guides, it is misleading to call a piece sterling silver unless it is “at least 925/1,000ths pure silver.” Look for a sterling or 925 mark, and ask when you don't see one.

The mine name, in writing

Mine names add value, which is exactly why they get borrowed. The Lowrys: “Mexican turquoise has been misrepresented and sold as Kingman turquoise since before the 1970s.” Their advice: “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.” The IACB says the same. Ask for a written receipt that lists the “name of the mine from which the turquoise was extracted” and “whether the turquoise is natural, stabilized, or treated.” New Mexico goes further than federal law here: its Indian Arts and Crafts Sales Act “requires the seller to disclose in writing the type of materials used.”

Who made it

If a piece is sold as Native American made, that claim is regulated. “Under the Act, it is illegal to offer or display for sale, or sell, any art or craft product in a manner that falsely suggests it is Indian produced, an Indian product, or the product of a particular Indian Tribe” (IACB, on the federal Indian Arts and Crafts Act of 1990). The same Act does not cover the stone: “the use of materials, such as turquoise, in the production of Indian art or craftwork is not within the scope of the Act.” So ask two separate questions, one about the maker and one about the turquoise. For more, see our guide to authentic Native American jewelry.

Myths that distort turquoise value

The Lowrys list common misleading statements that appraisers, salespeople, shopping networks and the press keep repeating (Turquoise: The World Story, p. 188). Three bear directly on price:

• “There is no natural turquoise left.” Wrong. The IACB puts natural turquoise at about 15% of world supply. It is scarce, not gone.
• “All turquoise needs to be treated to be usable and pretty.” Most does. Not all. The untreated stone is what commands the premium.
• “‘Clear shot’ stabilized turquoise produces a natural color.” A stabilized stone is a stabilized stone. It should be sold as one and graded as one.

Two more come from buyer's guides we have merged into this page:

• “Less than 10% of all turquoise mined is hard enough to be used in its natural state.” The IACB figure is about 15% natural, with about 85% too soft to cut or polish.
• “Copper often yields a vibrant, golden-brown matrix.” Copper and iron make the turquoise's color (Pogue). The matrix is host rock: “pyrites, quartz monzonite, iron oxides, and other host rocks” (Lowry).

A quick checklist before you buy

• Is it natural, stabilized, dyed or block? Get it in writing.
• Which mine, and does the stone have that mine's classic look? Get that in writing too.
• Is the color deep and even? Compare blue with blue and green with green.
• Is the matrix natural and even, or does it look painted?
• Is the silver marked sterling or 925?
• If a maker or tribe is named, is it documented?

Natural turquoise is its own subject: what natural turquoise is. When you know what you are looking for, browse turquoise set in sterling silver and ask us about any stone's mine and treatment.

Frequently asked questions

Sources

• U.S. Department of the Interior, Indian Arts and Crafts Board, with Joe Dan Lowry (Turquoise Museum). Indian Arts and Crafts Act turquoise consumer brochure (GPO gpo58769), n.d., pp. 1–2.
• Joe Dan Lowry & Joe P. Lowry. Turquoise: The World Story of a Fascinating Gemstone. 2010, pp. 109, 130, 179–180, 184, 187–189, 224, 231.
• Philip Chambless & Mike Ryan II. Turquoise in America: The Great American Turquoise Rush 1890–1910, Part 1. n.d., p. 182.
• Joseph E. Pogue. The Turquois (Memoirs of the National Academy of Sciences, vol. XII). 1915, pp. 7, 9.
• Federal Trade Commission. Guides for the Jewelry, Precious Metals, and Pewter Industries, 16 CFR § 23.5(b)(2).