Gemology

February 8, 2023 The British Crown Jewels with the Imperial State Crown center (1) and St. Edward's Crown (2) (Photo...

Recently, CNN spoke to independent diamond industry analyst Edahn Golan regarding the recent surge of lab grown diamonds. Golan revealed...

We reveal new custom details and photos of Rosalia's 4 carat round diamond engagement ring.

Gem formation usually involves mineral crystallization and other geological processes. Learn how these affect the gemstone properties gemologists study.

Explore gemstone hardness, wearability, and durability. Learn how hardness, cleavage, and settings affect jewelry use. Essential for smart gemstone choices....

Gemologists use several different gem classification methods. Learn how the most common systems work and what they cover as well...

The 10X loupe is the gemologist's best friend. Learn how to examine gemstones for fractures, inclusions, color, and much more...

A gem refractometer is the best tool for refractive index testing. Learn how to use this instrument to conduct this...

The spectroscope is one of gemology’s principal tools. Our basic spectroscope instructions will teach you how to operate and calibrate...

The optical properties of gems attract our eyes and can give a cut stone a unique character. However, gemstone physical...

Gemstone color measurements are hard to make with conventional color-order systems. Learn how recent colorimetry tech advances have improved accuracy....

Gemstone cleavage is a break in a crystal along internal planes. Learn the science behind this and the difference between...

Gem identification is part detective work, part art. Learn how gemologists can distinguish gem species and determine whether a stone...

How accurate are gem, mineral, and rock scanner identification apps? Our review covers the strengths and weaknesses of over 20...

Opal connoisseurs all have their favorite opal patterns. Learn how to identify the patterns of these beautiful gems with plenty...

What's the difference between synthetic, simulated, and created gemstones? Learn the definitions (and gray areas) of these commonly used terms....

Mined emeralds are expensive, so lab-made emeralds are an attractive option for consumers. Learn how these synthetic gems are made...

Identifying lab-created gems is a critical skill for gemologists. Learn how to spot the most common synthetic gemstone inclusions.

Disclosing enhancements to gems is a key duty for gemologists. Learn what are the hardest treatments to detect and how...

There are so many common gemstone treatments available today that keeping track of them can be difficult. This list and...

There's more to aquamarine color than blue. Most natural stones start blueish green and are heated to blue. Learn the...

How do gems likes rubies and red beryls get their red color? Learn the role impurity ions play in the...

HPHT diamond treatments can only be positively identified with costly equipment. However, you can learn to assess the probability that...

Explore the amazing world of gemstone photomicrography. These tips can help you view and photograph spectacular inclusions found inside many...

Garnet symbolism is rich and varied. The January birthstone has inspired many legends and popular associations with love, friendship, light,...

Emerald crystals can grow very large. Learn about some of the world’s largest emeralds, whether rough, faceted, or carved.

Are you looking for something truly unique for your next jewelry purchase? Explore these ten gemstones that are actually rarer...

Discover America's best gem hunting locations where you can unearth emeralds, diamonds, sapphires and more! Plan your gemology vacation with...

Headed out to the opal fields? Read on to learn more about opal prospecting and mining, plus some expert tips...

IGS member Richard Edley shares his experiences discovering California turquoise and offers advice on desert prospecting.

Natural alexandrite is popular and rare, which creates a market for synthetics. But is lab-created alexandrite real alexandrite? Learn the...

Our survey asked for your input on the age-old question: where is the line between ruby and sapphire? The results...

Uranium glass, or Vaseline glass, is a prized collector's item and is generally safe to handle. But is it safe...

Gem faceters and jewelry enthusiasts alike should learn about gemstone toxicity. This table has toxicity ratings for 280+ gems, based...

Refractive indices and double refraction (birefringence) help gemologists identify gems. The following table lists these values for selected gemstones.

Measuring specific gravity helps gemologists identify gemstones. The following table lists the specific gravity values for a variety of gem...