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 ...

珍珠生日石的意义和历史 这一迷人的六月生日石产自世界各地的海洋、湖泊和河流。这是永不过时的衣柜必备品，深受所有年龄阶段的女性热爱。珍珠的来源让我们的祖先着迷。中东地区的古人认为珍珠是从天堂滴落的眼泪。中国的传说宣称六月生日石取自龙的大脑。克里斯多弗·哥伦布（Christopher ...

Synthetic moissanite is much closer to diamond in overall appearance and heft than any previous diamond imitation; this article reports on how to identify and characterize it.

Emerald’s lush green has soothed souls and excited imaginations since antiquity.

Diamond is the only gem made of a single element: It is typically about 99.95 percent carbon. The other 0.05 percent can include one or more trace elements, which are atoms that aren’t part of the ...

Sharon Ament, director of the Museum of London, explains the Cheapside Hoard’s unique significance. She speaks of London’s importance as a nexus of trade between the Old World and the New World, and ...

Stability Alexandrite is stable under normal wearing conditions, which means it’s resistant to the effects of heat, light, and common chemicals. Cleaning Warm, soapy water is always safe for cleaning ...

Amethyst is the purple variety of the quartz mineral species and the gem most commonly associated with the color purple.

Thanks to its many varieties and rising value, rutilated quartz garnered attention at the 2014 gem shows in Tucson, Arizona.

Ruby is an incredibly durable gemstone if there are no treatment-related durability concerns. - Courtesy Jan Goodman Co. Hardness and toughness Gem and mineral hardness is measured on the Mohs scale.

The GIA Report Results API allows applications to integrate with GIA’s database in order to verify grading information and retrieve GIA report PDFs, images and other assets associated with a GIA ...

Changes resulting from heat treatment are stable and undetectable. Gems with abundant liquid inclusions can’t withstand heat treatment. Color changes due to irradiation can fade with exposure to heat ...