GIA’s laboratories use advanced instrumentation and research to deliver accurate grading, identification, and origin ...

5月の誕生石であるエメラルドは、復活と再開を連想させる宝石であり、千年以上もの間こよなく愛されています。緑色の定義として広くみなされているエメラルドの色ほど春にふさわしいものはありません。「エメラルドの島」というアイルランドの愛称 ...

This collection features more than 60 ornamental minerals of exceptional size and quality – many from localities with restricted access or that are no longer producing. Native Californian Joel Hauser ...

合成宝石材料是在实验室中制成的一种材料，但却具有与其相对应的天然矿物相同的化学、光学和物理特性，虽然在某些情况下，如合成土耳其石和合成蛋白石，可能会有其他化合物的存在。 自 19 世纪后期以来，就已经开始生产合成宝石晶体，其产品往往是 ...

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 ...

This large Australian light opal cabochon weighs 117.85 carats. Small play-of-color flashes of orange and green predominate in a pinfire pattern, with spots of a more muted blue over a grayish ...

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 ...

Consumers know diamond from the slogan “A Diamond is Forever”. With some care considerations this is relatively true. The Asscher cut was popular decades ago and is again a very popular cut style.

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, ...

People from all over the world send their diamonds to the GIA laboratory for grading and analysis. Our clients put their business in our hands and their trust in our expertise – and we are extremely ...

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 ...