The Graduate Gemologist ® diploma program taken via Distance Education is a combination of five online eLearning courses and three hands-on lab classes. Lab classes are offered at GIA campuses ...

Opal can range from 5 to 6.5 on the Mohs hardness scale. Hardness and toughness Gem and mineral hardness is measured on the Mohs scale. The numbers are based on the relative ease or difficulty with ...

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 ...

GIA’s D-to-Z color grading system is based on the relative absence of color. GIA’s Fancy colored diamond color grading is based on the presence of color. GIA describes color in terms of hue (the color ...

Citrine is one of the most popular yellow gems on the market. This designer cut shows off the warm glow of citrine’s sunny color. – Lydia Dyer, gem courtesy John Dyer & Co. Citrine—the transparent, ...

Diamond is available in a range of sizes and qualities to fit every consumer's tastes. One of the first things most people learn about diamonds is that not all diamonds are created equal. In fact, ...

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, ...

Emerald, the birthstone for May, has been beloved for millennia, evoking rebirth and renewal. Widely regarded as the definition of green, emerald is the perfect color for spring. From the poetic ...

Feldspar, from moonstone to sunstone to andesine, mineralogy and gemology articles. Abduriyim, Ahmadjan (2009) Characteristics of red andesine from the Himalaya ...

一月生日石柘榴石是品种最丰富的宝石之一，因为它有许多不同的颜色。柘榴石生日石可在世界各地进行开采，象征着许多不同的乐观情绪。了解更多关于这种独特生日石的信息。 紫水晶是二月生日石，是石英的紫色类别，据说可以预防醉酒，让人在生意中保持 ...

In 2009, GIA bestowed its highest honor, the Richard T. Liddicoat Award for Distinguished Achievement, on longtime chief research gemologist John I. Koivula. The award was based on his contributions ...

Those born in January are lucky to have the beautiful and diverse garnet as their birthstone. Garnets are commonly red but also come in an extraordinary range of beautiful colors, including orange, ...