Rock Discoveries

Uncovering the Mysteries: How to Identify Authentic Raw Turquoise

Turquoise has always been a highly sought after gemstone due to its stunning appearance. Its blue-green hue, intricate patterns, and unique qualities have made it a favored choice for jewelry, artwork, and even architectural design.

However, with so many varieties in the market, identifying raw turquoise can be a daunting task. In this article, we will explore four ways of identifying raw turquoise, namely its appearance, hardness testing, testing for treatments, and provenance.

Appearance of Raw Turquoise

One of the most obvious ways to identify raw turquoise is through its appearance. Turquoise occurs in various shades of blue and green, with each shade being an indication of its locality, host rock, and other natural factors.

For instance, Persian turquoise usually has a deep blue hue with black veins, while Arizona turquoise has a bright green hue with brown matrix. Furthermore, the texture of raw turquoise can also be a useful tool for identification.

Turquoise often forms as nodules or irregularly sized masses, embedded in a matrix of host rock. The intricate patterns of the matrix and the turquoise are unique to each deposit, which makes it easy to identify the stone’s origin.

Hardness Testing

Another way to identify raw turquoise is through hardness testing. Turquoise has a hardness of only 5-6 on Moh’s scale, making it susceptible to scratches, chips, and fractures.

However, gem-quality turquoise is harder, more durable, and resistant to damage. It can withstand a Moh’s scale hardness test, which involves scraping the surface of the stone with a mineral of known hardness.

Powdery material is another telltale trait of lower quality turquoise. When cut or drilled, it crumbles easily, often resulting in a powdery residue on the tools used for the process.

High-quality turquoise does not produce a powdery residue when cut, drilled, or polished.

Testing for Treatments

Stabilization is a chemical process often applied to raw turquoise to improve its durability and color. Understanding the various treatments applied to turquoise is crucial in identifying the stone’s originality and value.

For instance, reconstituted turquoise chips or fragments can be mixed with epoxy or other materials to create a solid stone. These often have a more uniform texture and color, unlike genuine stones.

To test for treatments, apply acetone to the surface of the turquoise. Genuine turquoise will not be affected, while reconstituted or stabilized stones will typically change color, dissolve, or emit an odor.


The final way to identify raw turquoise is through provenance. The quality and appearance of the turquoise vary according to the location of the mine.

For example, American turquoise mines, such as Sleeping Beauty, Bisbee, and Hidden Buffalo, yield high-quality turquoise with distinctive patterns and colors. Determining the mine location helps identify the origin, rarity, and value of the turquoise.

This knowledge is instrumental in ensuring that the buyer acquires a genuine, high-value raw turquoise stone. In conclusion, identifying raw turquoise can be a challenging task, considering the variety of stones available in the market.

However, observing the appearance, conducting hardness testing, verifying treatment, and determining the stone’s provenance are helpful tools in identifying genuine, high-quality raw turquoise. By following these steps, buyers can make an informed decision when purchasing raw turquoise, whether it’s for jewelry, art, decorative pieces, or any other purpose.

When purchasing turquoise, it’s essential to identify the stone’s authenticity, quality, and treatments applied to it. In this article, we will discuss different methods used to test the stone’s hardness, grading, and how to detect treatment.

Moh’s Scale

The Mohs scale of mineral hardness is a measure of a mineral’s resistance to scratching. The scale ranks minerals from 1 (softest) to 10 (hardest).

Turquoise ranks between 5 and 6 on the Mohs scale, making it a relatively soft gemstone. As a result, gem-quality turquoise has a higher level of durability and is resistant to wear and tear.

Copper and Steel Knife Tests

Scratching and testing turquoise hardness is an efficient way to distinguish between genuine turquoise and its natural imitations such as howlite. A copper or steel knife can be used to scratch the surface of the stone.

Genuine turquoise will not scratch because of its hardness, while howlite will scratch and leave behind a mark. Howlite is often used as a low-cost substitute for turquoise, and the scratch test is a quick way to differentiate between the two stones.

Acetone Test

The acetone test is used to identify whether turquoise has been dyed, particularly low-quality stones. To conduct the test, dampen a piece of paper towel with acetone and rub it against the surface of the turquoise.

Dyed turquoise will leave behind a color residue on the paper towel due to the dye being dissolved by acetone. Grading Turquoise on Moh’s Scale

Gemstones, including turquoise, can be graded using the Mohs scale.

This rating system ranks the hardness of the stone from 1 to 10, with 10 being the hardest. Turquoise grading on the Mohs scale is crucial when it comes to the value of the stone.

Generally, Turquoise ranges from 5 to 6 on Moh’s scale, but the higher its ranking on the Mohs scale, the more valuable it is. For example, a higher grade turquoise such as Sleeping Beauty turquoise is between 5 and 6 on the Mohs scale but can be classified as AAA when graded.

AAA turquoise is the most valuable, being almost perfect in terms of color, hardness, and lack of flaws.

Detecting Treatment


Stabilized turquoise refers to the process where a mineral stabilizer such as plastic polymer, epoxy, or resin is applied to the stone’s surface. This treatment enhances the stone’s color, durability, and hardness.

Moreover, stabilizing turquoise reduces its porosity, making it less vulnerable to aging, discoloration, or cracking or breaking.

To detect stabilization, observe the stone’s texture carefully.

The surface should feel smooth, glossy, and even. Burn tests indicate the stone’s authenticity since plastic or epoxy treatment can melt or leave a residue when heated.

Reconstituted Turquoise

Reconstituted turquoise is made by taking small fragments of turquoise and grinding them down into powder. The powdered turquoise is then mixed with a binding agent such as epoxy resin or plastic to create a solid block.

Although reconstituted turquoise has a similar appearance to natural turquoise, it feels different due to the use of binding agents. It often feels plastic-like, and the surface has a noticeable uniformity.

Acetone Testing For Dyes

The final method used to detect treatment in turquoise is through acetone testing for dyes. This test is useful for identifying dyed howlite, which is often used as an imitation of turquoise.

Cut a piece of turquoise and place it onto a damp paper towel. If the paper towel absorbs color, the stone is likely dyed.

In conclusion, understanding how to test the hardness, grade, and identify treatments in turquoise is essential, particularly for buyers who want to invest in genuine high-quality stones. It is important to use reliable and effective methods such as the Mohs scale, copper and steel knives, acetone testing, and careful observation to help identify and differentiate genuine sterling silver from its imitations.


Provenance is the origin or source of something, and in the gemstone industry, determining the provenance of a gemstone is crucial in determining its authenticity, rarity, and value. In this article, we will explore the importance of provenance in the turquoise industry and the methods used to determine the provenance of a turquoise stone.


Provenance is essential when purchasing gemstones such as turquoise because it plays a significant role in determining the stone’s cost, authenticity, and marketing. Gemstones from certain locations are often more valuable than others due to their rarity, quality, and the history behind them.

For example, turquoise from the Sleeping Beauty mine in Arizona is known for its unique hue and brilliance, making it highly valued by jewelry makers. In the industry, certain provenances can be used as a marketing tool to attract customers and increase sales.

For example, if a jeweler is selling turquoise, knowing its provenance allows them to inform potential buyers about its history, rarity, and uniqueness. This information often adds value to the stone, making it more valuable in the eyes of the buyer.


Determining a turquoise’s provenance requires a high level of expert knowledge and skill. There are various factors that gemologists and jewelers use to identify a stone’s provenance, including its color, texture, matrix, and geographical location.

However, identification of a stone’s provenance with a high level of certainty can be a complex task. Various turquoise mines can share similar features, making it difficult to pinpoint the exact provenance of the stone without expert knowledge.

Therefore, it is essential to use reliable and effective methods to help with identification.

Testing for Authenticity

Authenticating turquoise is a crucial aspect of identifying the stone’s provenance. Several tests can be used to distinguish between genuine turquoise and its imitations.

Heat Test

One of the most widely used tests for identifying turquoise is the heat test. Heat a needle and touch it to the surface of the stone.

Genuine turquoise will not be affected by the heat, while other imitations will melt or lose their color.

Scratch Test

The scratch test is also a useful technique in identifying genuine turquoise. Scratch the surface of the stone with a needle or an edge of a coin.

Genuine turquoise will leave a white scratch mark, while imitations, such as howlite, will scratch easily.

Acetone Test

The acetone test is often used to detect dyes and stabilizers that are applied to turquoise to improve their color or durability. Apply a small amount of acetone onto the stone’s surface and observe any color changes or markings left behind.


Testing for authenticity is not always straightforward, and certain stones may require more complex testing methods. For instance, simulant stones such as turquoise-colored glass and synthetic stones such as Gilson and Chrysocolla can be difficult to differentiate from genuine turquoise using basic testing methods.

Testing for authenticity has its limitations as some simulants and synthetics can show similar properties to genuine stones.

Expert Consultation

In cases where identification and authentication of turquoise are complex, it is always advisable to seek advice from a jeweler or gemologist. These professionals have specialized knowledge and instruments that they use to identify and authenticate gemstones.

In conclusion, identifying a turquoise’s provenance is vital in determining its authenticity, rarity, and value. The importance of provenance in the turquoise industry lies in its capacity to increase marketing potential and the stone’s rarity.

Certified professionals, such as jewelers and gemologists, have expertise and knowledge that they use to authenticate gemstones and determine their provenance. Successful identification of a turquoise stone’s origin requires a combination of expert knowledge, reliable testing methods, and attention to detail.

In conclusion, identifying and authenticating turquoise is essential for anyone looking to invest in gemstones or create unique pieces of jewelry. Testing for hardness, treating, and provenance can help identify genuine, high-quality raw turquoise.

Testing for authenticity has its limitations, and in complex cases, it is always best to consult a jeweler or gemologist.

Provenance can add value to the stone and is crucial in determining its rarity and history. Here are some FAQ’s to address common questions or concerns about identifying and authenticating turquoise:



How can I determine if a turquoise stone is genuine? – You can determine if a turquoise stone is genuine by conducting a heat test, scratch test, or acetone test.

2. How can I determine the provenance of a turquoise stone?

– Determining the provenance of a turquoise stone requires a high level of expert knowledge and can be identified by its color, texture, matrix, and geographical location. 3.

What is the importance of provenance in the turquoise industry? –

Provenance is essential in determining a stone’s rarity, quality, and the history behind it, which adds value to the stone and is used as a marketing tool by sellers in the industry. 4.

What should I do if I’m unsure how to identify and authenticate a turquoise stone? – If you’re unsure how to identify or authenticate a turquoise stone, it is recommended to consult a jeweler or gemologist who has specialized knowledge and instruments to help you.

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