How to Know if Turquoise is Real or Fake?

There is an abundance of fake turquoise in circulation. Some are far easier to identify than others. This article explains the different types of turquoise and tests that you can carry out at home that may help determine whether your stone is real or fake. Most tests used to determine whether a gemstone is genuine will cause some damage.

Ways to Identify Fake Turquoise

There are several tests that may help you to identify fake turquoise. If an imitation has been particularly well produced, as is often the case with some modern imitations from China, it can be far more difficult to identify.

No single test will confirm that a stone is genuine. If certainty is a priority, professional gemmological testing is the most reliable option. 

It's also worth noting that most tests carried out at home to identify fake minerals are likely to cause some amount of damage.

When trying to establish whether a turquoise stone is real, the first step is to examine the stone carefully, particularly around drilled holes, chips or worn areas. A jeweller's loupe or powerful magnifier would be useful.

Howlite and magnesite are naturally white or pale, so a stone that has been dyed to imitate turquoise could reveal its original colour beneath the surface. Dye can penetrate quite deeply, so the absence of any change in colour immediately below the surface does not necessarily mean the stone is genuine.

Acetone can be used on a small, inconspicuous area of the stone, preferably with a cotton bud, to reveal whether a stone may have been dyed. If nothing comes off, it doesn't prove the colour is natural. We experienced this after buying lapis lazuli from a new supplier. Although the stones had been dyed, the treatment was so advanced that the dye didn't come off.

A scratch test can help rule out some softer minerals used to imitate real turquoise. Turquoise has a hardness of about 5 to 6 on the Mohs scale, compared with howlite, 3.5 to 4.5 for magnesite and 3.5 to 4 for azurite. Chrysocolla is about 2 to 4, but can be considerably harder where the quartz content is high.

A natural piece of fluorite, which has a hardness of 4, will scratch howlite. It could also scratch other softer imitations but shouldn't scratch turquoise. The test becomes less reliable with low-grade turquoise, which can be softer, and with harder magnesite, which fluorite may not mark.

Even though howlite is generally very cheap, magnesite is even cheaper. A considerable amount of material being sold as howlite is actually magnesite.

When howlite or magnesite is dyed to resemble turquoise and sold openly as an imitation, it's labelled as Turquenite. Although sometimes described as a manmade stone, that's not correct. It's a natural mineral that has been dyed. 

To determine whether plastic or materials containing resin have been used in a piece of turquoise, heat the tip of a pin or needle and apply it to an inconspicuous area. Plastic may soften or melt and produce a distinctive chemical smell. Resin can react in a similar way.

Stabilised turquoise contains resin, as does reconstituted turquoise, so a reaction to heat does not necessarily mean the material contains no genuine turquoise.

A specific gravity test is also straightforward. However, water can damage turquoise or leave marks, particularly lower-grade stones which can be more porous. If carrying out this test, submerge the stone for as little time as possible and dry it thoroughly afterwards with a soft cloth.

The test requires a reasonably accurate digital scale, a container of water and a way of suspending the stone in the water. You'll need to be creative about how you do that because the best method will depend on its size, shape, and texture.

First, weigh the stone normally and record its weight in grams. Next, place a container of water on the scale.

Position whatever you're using to support the stone so that the part that will be submerged is already in the water, then reset the scale to zero. This prevents the support from affecting the measurement.

Place the stone in the support and lower it completely beneath the surface. It must not touch the sides or bottom of the container.

Record the reading on the scale, then divide the stone's original dry weight by this figure.

For example, if the stone weighs 12 grams and the submerged reading is 4.5 grams:

12 ÷ 4.5 = 2.67

Turquoise typically has a specific gravity of about 2.6 to 2.9. Air bubbles attached to the stone can affect the result, as can resin or other treatments.

Price can also be a useful warning sign. Turquoise sold very cheaply, particularly through online marketplaces by sellers whose identities and reputations cannot be established, is far more likely to be treated, reconstituted, or fake.

We have bought some very nice turquoise gemstones from India in the past, but they came from a supplier we've been doing business with for many years and have visited in person on numerous occasions.

The fake turquoise gemstones in this next photo were on a well-known website that sells licensed stock images. The photographer, whose collection was mostly diamonds, labelled them as "turquoise gemstones". They're synthetic and probably plastic.

Not all fake turquoise is quite as bad as this.

In a world where fake crystals, rocks, and minerals have become a hazard in this industry, trusting the supplier you buy from could be one of the safest ways to ensure your turquoise is genuine.