Vietnamese aquamarine is notable for its attractive color and well-formed crystals. Commercially significant deposits are known only from the Thuong Xuan District in Thanh Hoa Province, where the ...

Soon after it was first marketed in 1976, colorless cubic zirconia became the dominant diamond imitation, with current production of approximately 60 million carats per year. Although cubic zirconia ...

This ancient necklace dates to 2000BCE. An inscription on the center stone is a South Arabian script from the 8th century BCE. - From "Gems and Gemstones: Timeless Natural Beauty of the Mineral World" ...

This sapphire from Kashmir has an intense velvety blue color. – Photo: Robert Weldon/GIA. Sapphire is one of the Big three of jewelry colored gemstones—the other two are ruby and emerald. A durable ...

GIAは慈善的で非営利の501(c)(3)団体であり、誠実性、学術、科学、プロフェッショナリズムの最高水準を維持することにより ...

2月生まれの方の誕生石はアメシストです。アメシストは、何千年も人々を魅了しているクォーツの紫色の変種です。ライラックから深い紫色の色相を呈するアメシストは、多くの形やサイズにカットされます。また、採鉱されるのは勿論のこと、ラボで製造 ...