How to Identify Gems & Jewelry
Identifying gems and jewelry requires visually observing the four C's: cut, clarity, color and carat weight of a gem stone substance, as well as specific gemological procedures. Gems---petrified or mineral material used as jewelry---are considered precious because of their beauty, the extreme climate conditions over millions of years that created them and the rarity of such conditions reoccurring. To determine the value of your gemstone---and whether or not the stone is a gem in the first place---learn some valuable identification techniques. Does this Spark an idea?
Things You'll Need
- Gemstone hardness kit
- Refractometer
- Gem stone cloth
- Incandescent light source
- Ultraviolet light source
- Pen light
- Tweezers
- 10 power loupe
- "Gem Identification Made Easy"
Instructions
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Examine your gemstone substance and evaluate it, holding it with tweezers and keeping it clean throughout the testing process with a gemstone cloth: the better the color, cut, clarity and weight, the higher the value. Hard and crystalline in structure, gems can only be shaped by cutting, fracturing or abrasion. If your test substance has a rough and sandy surface, it is not a gemstone. If you can easily bend or crush it, you probably have a metallic ore. Pearls and petrified wood do not constitute gemstones.
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2
Test the hardness of your gem stone substance with a hardness kit that ranks mineral hardness on the commonly accepted "Mohs Scale," which measures the hardness of a mineral substance on a scale of one to 10 (talc to diamond, respectively). Test the hardness of your substance by scratching it with a series of test substances from the hardness kit to determine approximate hardness and further determine its identity.
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3
Using a microscope, look closely at your gem stone substance for inclusions---different bands of color in a gem or mineral. Unique to each mineral species, inclusions provide a key to identification, including distinguishing between natural and synthetic materials. Look for common inclusions such as clouds, needles or crystals of color, which usually indicate a real gemstone.
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Use a loupe 10 power gemological tool with a triplet lens to identify surface characteristics such as inclusions. Lines and bands on the gemstone substance further determine the species to which the stone belongs.
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Use a refractometer to determine the stone's refractive index (RI)---the angle and speed of light as it passes through a gem substance. Compare the RI in the gem substance with the categories on a gem property chart to calculate the gem species.
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Use a handheld ultraviolet light source to view the gemstone substance to determine whether it is fluorescent or phosphorescent. The strength and color of the fluorescence indicate the species of the stone and also whether it incorporates natural or synthetic material.
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Use a gemstone reference guide such as "Gem Identification Made Easy," by Antoinette L. Matlins and Antonio C. Bonanno, for additional help. This reference includes a refractive index, specific gravity tables, step-by-step instructions for using gemological tools and instructions on how to spot synthetic stones.
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