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 ...

The 75.47-carat Hooker Emerald was worn by Ottoman Sultan Abdul Hamid II, the last sultan of the Ottoman Empire. Photo by Chip Clark, courtesy Smithsonian Institution, National Museum of Natural ...

光临位于图森宝石矿物展广场层的 GIA 展位 (128 G)，了解教育、鉴定所服务、 《宝石与宝石学》 (Gems & Gemology) 、零售商支持、仪器和 GemKids 等方面的最新信息。 在 GIA 展位与工作人员交流有关教育的信息并观看 GIA 宝石学的网络学习课程演示。 探秘 GIA 提供的鉴定所服务，了解有关宝石鉴定所需仪器 ...

这种 Ib 型钻石原石来自西非塞拉利昂和利比里亚边界附近的 Zimmi（兹密），它含有的硫化物内含物的化学成分能为西非大陆的形成提供线索。摄影：Karen Smit（卡伦·斯密特）/GIA。 本文是 Sulfur Isotopes in Diamonds Reveal Differences in Continent Construction （《钻石中的硫同位素揭示大陆构造差异》）一文的摘要 ...

虽然珍珠可以呈现出各种天然色彩，而且色度很高，但还是可以处理珍珠的颜色来改变其外观。最常见的颜色处理方法是染色，这种方法更常用于淡水珍珠，海水珍珠则较少使用。 虽然淡水珍珠确实可以呈现出各种美丽的天然色彩，而且色度也可能很高，但它们通常不会呈现天然的深色调，除暖 ...

Gemological LibraryResources The library provides a wide variety of gemstone-and-jewelry-related resources for students, staff, researchers, alumni, members of the industry, and the general public.

镁铝榴石和铁铝榴石的颜色范围从紫色到橙红色。 锰铝榴石是各种橙色的宝石类别，而钙铁榴石则为黄色到绿色。 钙铝榴石具有广泛的色彩范围，从无色、黄色至红橙色和橙红色，再到强烈的、鲜艳的绿色。

Cultured pearls come in different sizes, shapes, and colors. Perhaps the best-loved gems of all time, pearls—both natural and modern cultured pearls—occur in a wide variety of colors. The most ...

If you were born in February, your birthstone is amethyst – the purple variety of quartz that has captivated mankind for millennia. Its lilac to deep purple hues can be cut into many shapes and sizes, ...

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 ...

Expert, comprehensive analysis of your jewelry items. These services include assessments of natural D-to-Z diamonds, offering details such as estimated total carat weight, color and clarity ranges.

Graduate Jeweler Program The Graduate Jeweler diploma program is a hands-on experience that introduces students to the knowledge and skills required for a career in jewelry fabrication and repair. You ...