As a consumer, you will regularly encounter in the marketplace gems that have been treated to change their appearance. A topic that often comes up is whether a particular gemstone is or isn’t treated.

Search a city or postal code to find retailers who carry GIA-graded diamonds or have GIA-trained staff. Results will include addresses, store hours and directions. Store hours reflected on Retailer ...

Cubic zirconia can be produced in large sizes and in different colors. These colorless and pinkish purple CZ are, from left to right, 44.49 carats, 29.86 carats and 54.60 carats. Photo: Tino Hammid.

Harness the power of knowledge with the industry-leading instruments that GIA uses in its grading laboratories. Representing more than 85 years of research and the combined expertise of GIA’s ...

Students examine the technical expertise needed to grade, buy, and sell diamonds with the insight of a seasoned professional. Coursework explores the GIA diamond grading procedures to assess the 4Cs – ...

GIA is proud to provide the most comprehensive research in the industry with a world-renowned field gemology team and a dedication to acquiring colored stones directly from the source. Our ...

Emeralds are again being mined in the historic district of the Ural Mountains. Physical, chemical, spectroscopic, and microscopic characteristics of stones from the recent production are presented and ...

Synthetic emeralds grown hydrothermally in an alkali-free, chlorine-bearing solution have been manufactured in Guilin, China, since 1987. Diagnostic microscopic features include growth and color ...

Attractive yellow to light greenish yellow gem scapolites have been mined from a skarn deposit near the town of Ihosy, in southern Madagascar, since the late 1990s. Chemical analysis indicates that ...

誕生石は、楽しくて人気のあるカラフルな方法で宝石の世界へと導いてくれます。性別、年齢、国籍、宗教を問わず、世界中の人々を魅了します。誕生石は、それぞれの宝石特有の秘密 ...

GIA通信教育では、現在と同じ生活をお過ごしになりながら、宝石とジュエリーの資格を得て専門家としての知識を広げることができます。 通信教育の仕組み メディア豊富な教材が ...

GIA グラジュエイト ジェモロジスト オンライン ディプロマ コースワークは、ダイヤモンドとカラーストーンに関する包括的な宝石学教育を提供します。最新の宝石学機器を使用し、学生は ...