A cut gemstone with intense chatoyancy that originated from Sri Lanka was determined to be a member of the scapolite solid-solution series. Indices of refraction and unit-cell dimensions were found as ...

Pink-to-red coral has a long history as an ornamental gem material in jewelry, carvings, and sculptures. However, due to a variety of environmental and legal factors, the supply of high-quality, ...

GIA Instruments works hand-in-hand with GIA’s laboratory, education and research teams, as well as the jewelry trade to develop the instrumentation you need to prepare you for the challenges of ...

The separation of naturally colored lavender jadeite from color-treated material is a problem that has long plagued gemologists. One theory is that the dyeing agents being used are of an organic ...

CARLSBAD, California – January 14, 2025 - The Gemological Institute of America (GIA) has announced the planned retirement of its president and CEO, Susan Jacques, at the end of 2025. The Institute has ...

Although individual companies might create their own quality descriptions, like AAA, AA and A, to denote the range of quality of their goods, no standard quality-grading scales exist for peridot.

Jadeite comes in a wide range of colors. The most valuable is an intense green called Imperial. - Courtesy Mason-Kay Fine Jade Jewelry To understand the value of jade, you have to look beyond its ...

However gem quality diamonds are fashioned from the original crystal shape they possess a combination of brightness, sparkle, fire, and sense of purity not matched by other gems. - Jeff Scovil, ...

Verifying the gold content of karat-gold jewelry is a problem for the entire industry. This study compares four widely available testing methods: density (measured by hydrostatic weighing), chemical ...

After you have been issued the I-20MN from GIA, you will need to contact the U.S. Consulate in your home country to apply for the M-1 visa. Your dependents will need an M-2 visa. Please contact the ...

This 7.19-carat alexandrite was cut to feature its beautiful color change. When the light source changes from daylight to incandescent light, the gem’s color changes from bluish green to reddish ...

这条镶嵌着祖母绿和钻石的装饰艺术 (Art Deco) 风格项链制作于 1935 年左右，据说是梵克雅宝为美国名媛收藏家 Hélène Beaumont（爱莲・博蒙）量身定制的。照片由苏富比友情提供 虽然各大拍卖行仍 ...