Carat weight, or mass, is just one of many gemstone properties measured at GIA (box A). Measurements of physical dimensions and facet angles of polished gemstones, assessment of color and ...

ABSTRACT In southeast Vietnam, gem-quality anorthoclase is found as megacrysts in Cenozoic alkali basalt. The crystals are transparent to translucent with vitreous luster and can be near-colorless, ...

Large pearls of either natural or cultured origin with hollow structures have occasionally been detected in laboratories, often filled with foreign materials such as resin, metals, shells, and even ...

At the GJX show, Pillar & Stone (San Francisco, California) offered bright green jade from Guatemala, confirmed to range from jadeite to omphacite, that was highly translucent to nearly transparent.

CARLSBAD, Calif. – June 20, 2025 – The Board of Governors of the Gemological Institute of America, Inc. (GIA) has named Pritesh Patel, currently GIA’s Chief Operating Officer, as the Institute’s ...

Pursue your passion Whether you’re taking the next step in your professional journey or starting a new career, GIA courses and diploma programs prepare you for success. We offer the finest gem and ...

Reports and Services available for jewelry.Jewelry Report Designed for clients who seek in-depth insights into every aspect of a jewelry item. Comprehensive analysis of the diamonds in an item, ...

ONLINE EDUCATION PAYMENT PLANS Tuition payment plans are available for the online courses listed below with the first installment and a non-refundable $35 plan administration fee due at the time of ...

Developed by the Harvard Business School (HBS), the program focuses on new research and best practices to deliver practical value and actionable techniques. Participants learn using the HBS case study ...

以下是 GIA 将休业的法定假期列表。 2025 年 5 月 5 日（星期一） 玛哈•哇集拉隆功国王陛下加冕（补假） 2025 年 5 月 12 日（星期一） 卫塞节（补假） 2025 年 6 月 3 日（星期二） 王后陛下诞辰 2025 年 7 月 10 日（星期四） 守夏节 ...

ハーバード・ビジネス・スクール（HBS）により開発されたこのプログラムは、新しいリサーチとベストプラクティスに焦点を当て、実践的な価値と実行可能なテクニックを提供します。参加者は、ハーバードの膨大なビジネス・インテリジェンス・リポジトリーを活用したHBSのケース・スタディ ...

关于 GIA GIA（美国宝石研究院）是成立于 1931 年的独立非营利机构，被公认为世界上最权威的宝石学机构。GIA 研发了著名的以颜色、净度、切工和克拉重量为标准的 4C，并于 1953 年创建了全球公认的国际钻石分级系统™，作为钻石品质的标准。 GIA 积极投入研究、教育、宝石鉴定所服务以及仪器研发 ...