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gemstone luminescence
What is Gemstone Luminescence?

Gemstone luminescence is a glow that occurs when certain stones are subjected to energy such as UV light. This effect can help gemologists identify gems.

natural alexandrite - engagement ring
Alexandrite Value, Price, and Jewelry Information

Everything you ever wanted to know about alexandrite. Find value guidelines, scientific data, expert comments, and more in our Gemstone Listings.

ten gemstones rarer than diamond - paraiba ring
Ten Gemstones Rarer than Diamond

From the seemingly common to the utterly obscure, you wouldn't guess these ten gemstones are rarer than a diamond! If you're looking for something unique for your next jewelry purchase, check out these ten stunning gemstones rarer than diamond.

alexandrite - round-cut alexandrite ring with diamonds
Alexandrite Buying Guide

Vivid color change makes alexandrite one of the world’s most coveted stones. Our alexandrite buying guide can help you find the best gem for your budget.

chrysoberyl varieties - color-change chrysoberyl
Is My Alexandrite Just A Color-Change Chrysoberyl?

Buyer beware! Not all color-change chrysoberyl is alexandrite. Learn the classic color ranges of true alexandrite and avoid being scammed by marketers.

How Can A Gemstone’s Optic Sign Change?

A gemstone's optic sign may be listed as either + or -. Learn whether impurities in a specific stone or the choice of axes to measure RI cause the change.

Is Synthetic Alexandrite Real Alexandrite?

Natural alexandrite is rare, creating a market for synthetics. But are synthetics real alexandrite? Learn about natural, synthetic, and real gems here.

Are There Any Fair Gemstone Pricing Formulas?

Can gemstone pricing formulas help gem merchants and buyers make fair deals? Learn what factors can affect gem prices.

Understanding Gem Synthetics, Treatments, And Imitations, Part 4: Synthetic Gemstone Guide

Many varieties of gems besides diamond can be created in the laboratory. Our synthetic gemstone guide covers many examples and explains their manufacture.