Discovering The Authenticity Of Your Peridot Gem


Peridot, or as the ancient Egyptians called it “the gem of the sun” is a brilliant olive-green gem. Unlike many gemstones, it is one of a few that only comes in that shade of green. It can, however, have a yellow or brown tint. This gem is formed in volcanic magma and it is the iron within it that gives it its color.

Special Property

It is mist covered and this is easily visible with a magnifying glass. If the Peridot is described as any other color, this is the first sign that a fake is in question. Another important property of Peridot is that the color does not change whether it is seen in natural or artificial light.

How to Discern Genuine Period-It Is Mist Covered

Simple Tests

Although peridot has never been recreated in the laboratory, glass imitations do exist. Many simple tests are available so you can test the authenticity of your stone.

The Eye Test

Look carefully at the gem. True Peridot is green. Take it outside, if the color doesn’t change between daylight and artificial light, it’s a good sign. Another important factor is the presence of a yellow or brown tint. Even the best peridot has a slight yellow tint. Finally, all natural Peridot contains some cracks and a slight mist. This gemstone is quite soft and so natural wear and tear applies. All peridot has inclusions as well. If the stone is perfect with no inclusions and no cracks, the stone is a fake.

How to Discern Genuine Period-The Eye Test

Simple Refraction Test

Although you cannot test the refraction index without a refractometer, you can see if the stone has a double refraction easily. Look at the stone closely. You can use a magnifying glass if necessary. Look through the stone towards a single light source like a light bulb or torch. You should see either a single or double ray of light within the stone. A double ray means that the stone has a double refraction and is a peridot gem. A single ray means there is no double refraction and you are looking at glass.

The Gemology Test

This test can easily be done at home. Because Peridot contains iron, you can use a magnet in the following order to know for sure. Place the stone on Styrofoam in a water basin. It should be floating in the middle of the dish. Take a magnet, a relatively strong one will do, and try to drag the stone. If the stone moves towards the magnet, even slightly, you have a real Peridot.

Peridot Vs. Cubic Zirconia

Green Cubic Zirconia (CZ), the man-made material, and peridot can look strikingly similar. Knowing the difference between the two will help you make the distinction. Price is the easiest way. High-quality peridot costs about $500 per carat, while CZ cost much less. Real peridot has tiny inclusions and cracks. Even the highest quality of peridot will have some imperfections. Zirconia is man-made, new, and flawless. Finally, CZ is a very hard substance with an 8.5 on the Mohs scale. Peridot ranges from 6.5 to 7.9.

Lab Tests

How to Discern Genuine Period-Fake Peridot vs Genuine Peridot

Each gemstone has specific attributes like its composition, its specific gravity, and refraction. To determine which gem is in question, these are tested.

To test the stone for Peridot, the following steps are taken. First, the color, clarity, and the saturation. This is noted. The first test done is often the refractive index test. For this, a refractometer is used. Peridot has a refractive index of 1.65-1.073. This is similar to 4 other stones, so further testing is done. Then they may choose to test the specific gravity or density. This is done by weighing the stone in the air and immersed in a liquid. This is then calculated. Peridot falls between 3.28 and 3.48. This is usually enough information. All data is put together and by a process of elimination, the stone is identified. So let’s say our stone is olive green, has a refractive index of 1.67 and a density of 3.4. By color alone it can be any stone including glass. Two stones have the same color and RI. That is Peridot and Tashmarine Diopside. However, Tashmarine has a much lower density, so we know the stone is a Peridot. Glass also has its own RI and density so if the stone is fake it can be spotted easily by applying these tests.