Specific Gravity Values of Selected Gems
Measuring specific gravity helps gemologists identify gemstones. The following table lists the specific gravity values for a variety of gem…
Azurite Value, Price, and Jewelry Information
Collectors prize deep blue azurite crystals, but faceted gems are extremely rare. However, azurite frequently occurs mixed with green malachite,…
Alternative Birthstones
Not happy with your birthstone? Explore these alternative birthstones associated with astrological signs, angels, the hour or day of your birth,…
Turquoise Value, Price, and Jewelry Information
With striking sky blue to blue-green colors, turquoise has been prized by cultures all over the world for over 5,000 years. Today, the traditional…
Table of Refractive Indices and Double Refraction of Selected Gems
Refractive indices and double refraction (birefringence) help gemologists identify gems. The following table lists these values for selected…
Sugilite Value, Price, and Jewelry Information
What is the color of sugilite? Grape jelly purple is a good description. More popular among consumers in Asia than North America, this is a very rare…
Gem Formation: How are Gemstones Created?
Most gems form naturally as minerals within the Earth. Most form as crystals, solids whose atoms are arranged in highly ordered repeating patterns…
The Physical Properties of Gemstones
Step 2: Advanced Gemology Lesson 2 Back to syllabus The optical properties of gems attract our eyes and can give a cut stone a unique character. However,…
Grading Gem Carvings
Gem carvings vary widely in size, shape, and quality. You can find small, simple carvings with a glued-on bail for just a couple of dollars. Fine…
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