Jade Buying Guide

Peridot Buying Guide

Sphalerite Buying Guide

Lapis Lazuli Buying Guide

Morganite Buying Guide

Emerald Buying Guide

Kunzite Buying Guide

Diamond Rating: A Beginner's Guide

Tridacna Pearl Buying Guide

Sapphire Buying Guide

Spinel Buying Guide

Ammolite Buying Guide

Citrine Buying Guide

Malaya Garnet Buying Guide

Agate Buying Guide

Zircon Buying Guide

Turquoise Buying Guide

Opal Buying Guide

Chrysoprase Buying Guide

Quahog Pearl Buying Guide

Tanzanite Buying Guide

Pearl Buying Guide

Rutilated Quartz Buying Guide

Melo Pearl Buying Guide

Crystalline Quartz Buying Guide

Demantoid Garnet Buying Guide

Moonstone Buying Guide

Garnet Buying Guide

Precious Coral Buying Guide

Aquamarine Buying Guide

Alexandrite Buying Guide

Amethyst Buying Guide

Amber Buying Guide

Oregon Sunstone Buying Guide

Blue Tourmaline (Indicolite) Buying Guide

Rubellite Tourmaline Buying Guide

Chrome Tourmaline Buying Guide

Green Tourmaline (Verdelite) Buying Guide

Tourmaline Buying Guide

Watermelon Tourmaline Buying Guide

Topaz Buying Guide

Paraíba Tourmaline Buying Guide

Creating an Ethical Engagement Ring: the Complete Guide

Padparadscha Sapphire Buying Guide

Conch Pearl Buying Guide

Iolite Buying Guide

Ruby Buying Guide

Detailed gem buying guides with example pictures and gem prices. Covers color, clarity, cut, carats, origin, values, wholesale and retail prices, and more.

Gem Buying Guides

Agate

Chalcedony

Fire Agate

Fossilized Organisms

Iris Agate

Alexandrite

Chrysoberyl

Amber

Amethyst

Ammolite

Aquamarine

Tourmaline

Chrysoprase

Citrine

Calcareous Concretions

Conch Pearl

Saltwater Pearl

Ametrine

Prasiolite

Quartz

Rock Crystal

Rose Quartz

Rutilated Quartz

Smoky Quartz

Tourmalinated Quartz

Demantoid Garnet

Diamond

Diamond Rating: A Beginner&#8217;s Guide

Emerald

Almandine Garnet

Almandine-Pyrope

Andradite

Andradite-Grossular

Chrome Pyrope

Color Change Garnet

Gadolinium Gallium Garnet

Garnet

Grossular Garnet

Hessonite

Hibschite

Hydrogrossular Garnet

Malaia Garnet (Malaya Garnet)

Mali Garnet

Mandarin Garnet

Melanite

Proteus

Pyrope Garnet

Pyrope-Spessartine

Rhodolite Garnet

Spessartite Garnet

Topazolite

Transvaal Jade

Tsavorite Garnet

Umbalite

Uvarovite Garnet

Yttrium Aluminium Garnet

Cordierite

Iolite

Jade

Jadeite

Maw Sit Sit

Nephrite

Kunzite

Spodumene

Lapis Lazuli

Feldspar

Labradorite

Moonstone

Peristerite

Morganite

Opal Stone

Oregon Sunstone

Padparadscha Sapphire

Cuprian Elbaite

Paraíba Tourmaline

Freshwater Pearl

Mother of Pearl

Pearl

Peridot

Coral

Organic Gemstones

Rubellite

Ruby

Sapphire

Sphalerite

Spinel

Tanzanite (Zoisite)

Zoisite

Topaz

Chrome-Tourmaline

Elbaite

Indicolite

Verdelite

Watermelon Tourmaline

Turquoise

Hyacinth

Starlite

Zircon

In 2012, Donald Clark retired and passed along stewardship of the IGS to Seth and Lisa Rosen. Seth and Lisa were longtime members of the IGS. Seth is a gem collector and active Internet entrepreneur, who had already spent a great deal of time in the custom jewelry business. He founded <a href="https://www.custommade.com/">CustomMade, the world’s largest online custom jeweler</a> and also operates <a href="https://www.ganoksin.com/">The Ganoksin Project, a technical resource website for bench jewelers and jewelry manufacturers</a>. Seth and Lisa felt strongly that the IGS needed to remain a cost-effective, accurate, and comprehensive resource for all those interested in gemology. IGS is our passion, and it is a family business.

Seth and Lisa Rosen

The late Donald Clark, CSM founded the International Gem Society in 1998. Donald started in the gem and jewelry industry in 1976. He received his formal gemology training from the Gemological Institute of America (GIA) and the American Society of Gemcutters (ASG). The letters &#8220;CSM&#8221; after his name stood for Certified Supreme Master Gemcutter, a designation of Wykoff&#8217;s ASG which has often been referred to as the doctorate of gem cutting. The American Society of Gemcutters only had 54 people reach this level. Along with dozens of articles for leading trade magazines, Donald authored the book &#8220;Modern Faceting, the Easy Way.&#8221;

Donald Clark, CSM IMG

Jeffery Bergman, SSEF SGC, founder and director of <a href="http://www.primagem.com/">8th Dimension Gems</a> in Thailand, is an American gem dealer with more than 40 years of experience in gemstone and fine jewelry mining, cutting, wholesaling and retailing. His career has taken him to more than 50 countries and every continent except Antarctica. He has appeared on the BBC, CNN, NBC, ABC and GEO; and has been featured in Time, USA Today, National Geographic, Gems &amp; Gemology and Discovery Channel magazine. He is a regular guest speaker at gem lab seminars and gemological association conferences and universities.

Jeffery Bergman, SSEF SGC

Dr. Joel E. Arem has more than 60 years of experience in the world of gems and minerals. After obtaining his Ph.D. in Mineralogy from Harvard University, he has published numerous books that are still among the most widely used references and guidebooks on crystals, gems and minerals in the world.
Co-founder and President of numerous organizations, Dr. Arem has enjoyed a lifelong career in mineralogy and gemology. He has been a Smithsonian scientist and Curator, a consultant to many well-known companies and institutions, and a prolific author and speaker. Although his main activities have been as a gem cutter and dealer, his focus has always been education. <a href="https://www.joelarem.com/">joelarem.com</a>

Joel E. Arem, Ph.D., FGA

Fatma Oya Borahan, GG, FGG has Graduate Gemologist and Diamond Diplomas from the Gemological Institute of America (GIA) the German Gemmological Association (DGemG) and Gemmological Association of Great Britain (GemA). <a href="http://birdamlasu.com/">birdamlasu.com</a>

Fatma Oya Borahan, GG, FGG

Barbara Smigel is a GIA certified gemologist, facetor, jewelry designer, gem dealer, gemology instructor and creator of the well-regarded educational websites <a href="http://www.acstones.com">acstones.com</a> and <a href="http://www.bwsmigel.info">bwsmigel.info</a>.

Barbara Smigel, PhD. GG

Dr. Gerald Wykoff is GG (Graduate Gemologist), a CSM (Certified Supreme Master gemcutter), educator, and author of several gemology books. He founded the American Society of Gemcutters in the 1980s and served for more than 10 years as the editor of its monthly magazine, American Gemcutter.

Dr. Gerald Wykoff GG CSM

A geologist, environmental engineer and Caltech graduate, Addison&#8217;s interest in the mesmerizing and beautiful results of earth&#8217;s geological processes began in her elementary school&#8217;s environmental club. When she isn&#8217;t writing about gems and minerals, Addison spends winters studying ancient climates in Iceland and summers hiking the Colorado Rockies.

Addison Rice

The late Jeff Graham was a prolific faceter, creator of many original faceting designs, and the author of several highly-regarded instructional faceting books such as <a href="https://rockpeddler.com/product-category/instructional-materials/">Gram Faceting Designs</a>.

Jeff R. Graham

Bear Williams, CG, FGA (Hon), is President and Laboratory Director at <a href="https://stonegrouplabs.com/">Stone Group Laboratories</a>. Bear travels to gem producing countries and treating regions researching the latest trends in gemology and visiting with other lab directors. On-site research allows him to keep abreast of new synthetics and treatments in the marketplace. He regularly meets with other gemological associations and labs, and together will present research findings, and discuss the latest nomenclature or laboratory issues relevant to the trade and consumers. Recognized as an expert in the field of digital spectroscopy, Bear operates UV-Vis-NIR, ED-XRF, FTIR, UV, and Raman Spectrometers.

Bear Williams

Cara Williams, FGA, is Vice-President and Senior Staff Gemologist at <a href="https://stonegrouplabs.com/">Stone Group Laboratories</a>. Cara is a fellow of the Gemmological Association of Great Britain (Gem-A). She has been a tutor for the prestigious Diploma in Gemmology course for the Gem-A in London for more than 15 years. Growing up in a retail jewelry family with a concentration in colored stones, Cara has been in the wholesale trade since 1986. She brings a lifetime of experience working with gems to the lab, her students, and many published articles.

Cara Williams

Kyrylo Gubariev, Graduate Gemologist (GG, AJP) is a gemologist with a passion for sharing his knowledge with fellow gem lovers. Originally from Ukraine, he is currently based in Bangkok, Thailand.

Kyrylo Gubariev, Graduate Gemologist (GG, AJP)

Appraisals

Gem Cutting

Gemological Laboratories

Gemstones

Rough Gems and Mineral Specimens

Jewelry

Gemology Supplies and Equipment

Auctions

Gem Treating

Informational Resources

Lapidary Supplies and Equipment

Special Services

An Introduction to Gem Identification

Destructive Gemstone Testing

Enhanced Gem Inclusions

Identifying Synthetic Diamonds

Lapidary Technology Through the Ages: Laps and Polish

Why are Topaz and Citrine Gemstones Misidentified?

Identifying Garnets Simplified

Staurolite Value, Price, and Jewelry Information

Is This a Fossil?

How Common is this Sapphire Coloring?

A Suffragette Pendant

Ruby or Sapphire?

For Professionals and Dedicated Enthusiasts

Free Professional Business ListingGet your company in front of 12,000 gem enthusiasts and professionals.

Gemstone Buying GuidesAdvice that you can trust written by industry experts, without the giant price tag.

Professional Certification ProgramsOnly IGS Professional members are eligible to enroll in Professional Certification Programs (additional $400 per certification course)

More Advanced Filters in our Gem GalleryFilter images based on all of the basic filters PLUS Transparency, Multi-Color, Pleochroism, Phenomena, Treatment, and Inclusions

Gem Identification GuidesBe confident in what you have and avoid the heartbreak and cost of identification mistakes.

Professional