NextGem Holiday Prep Campaign

Fast-Track Your Seasonal Hires

Diamond Training from GIA NextGem™

Start Here
November Birthstone

Fall’s Golden Child: Sunny Citrine and Fiery Topaz

November Birthstone

LEARN MORE
2025 Holiday Campaign

Complimentary Next-Day Service on Diamond Reports
Plus Loose Diamond Display Case

U.S. Only

Learn More
Jewelry Services HPH

Limited-Time Offer:
Buy One Jewelry Report,
Get One Half Off

Learn More
SU25 GG Issue Cover

Phenomenal Gemstones, Gem Granitic Pegmatites, and Spotlight on Ben Kho

New Gems & Gemology Issue

READ MORE
featured

Research & News

Tahitian Pearls
Retailer Resource

How GIA Analyzes Pearls from Start to Finish

Easy, step-by-step guide to how GIA analyzes pearls in its laboratory.
Read More

Starry Night
Retailer Resource

How GIA Grades Colored Stones from Start to Finish

Easy, step-by-step guide to how GIA analyzes colored gemstones in its laboratory.
Read More

Many loose laboratory-grown diamonds glowing under short-wave uv light
Retailer Resource

Testing Diamonds and Gems using UV Light

Quick how-to guide for retailers to test gemstone fluorescence and help identify stones in their own stores.
Read More

Figure 6. This selection of deep-UV fluorescence images of natural diamonds highlights the wide range of potential emission patterns and colors that can be observed, evidence of diamond’s unique growth and residence history. E: Most natural type II diamonds show blue fluorescence with mosaic-like polygonized dislocation patterns, differing from characteristic type II CVD- or HPHT-grown diamond patterns (compare with figures 8–10). Images by Garrett Koneval (A), Najmeh Anjomani (B), Wuyi Wang (C), Christopher Vendrell (D), Ulrika F.S. D’Haenens-Johansson (E), and Sandeep Kabariya (F).
Glowing Gems - What Does Fluorescence Tell Us?

G&G in a Flash: What Does Fluorescence Tell Us?

Learn about the principles, mechanisms, and characteristics of luminescence that create the impressive and memorable glow of gemstones.
Read More

CVD diamond plate and HPHT laboratory grown diamond
Laboratory-Grown Diamonds Update

The Latest on Laboratory-Grown Diamonds

Learn the latest trends by GIA on the laboratory-grown diamond industry.
Read More

Hand holding demantoid garnet rough in matrix.
Field Gemology Update

The Latest in Field Gemology from Wim Vertriest

Learn the latest on Madagascar sapphires and demantoid garnets from Wim Vertriest, GIA Manager of Field Gemology.
Read More

Learn & Connect

Learn How To Buy

Engagement Rings

Discover

Diamond Origin

Use our labs to

Verify a Stone

Download

Gems & Gemology
This Month's

Featured Gems

Featured Gem Peridot
Peridot

Found in lava, meteorites, and deep in the earth’s mantle, yellow-green peridot is the extreme gem.
Fancy Color Diamond
Fancy Color Diamond

Dazzling brilliance. Captivating color. These are the planet’s most valued gems.
Diamond
Diamond

Diamonds are among nature’s most precious and beautiful creations.
Emerald Bluish Green Stone
Emerald

Emerald is the bluish green to green variety of beryl, a mineral species that includes aquamarine.
Featured Gem Citrine
Citrine

Citrine is the transparent, pale yellow to brownish orange variety of quartz.

View the Gem Encyclopedia