Explore sapphire history, research, quality factors, and more in the GIA Gem Encyclopedia.

There are other green gems, like tourmaline and peridot, but emerald is the one that’s always associated with the lushest landscapes and the richest greens. Ireland is the Emerald Isle. Seattle, in ...

探索五月生日石 — 祖母绿的意义和历史及产地。

Emerald is 7.5 to 8 on the Mohs scale and has fair to good toughness, making it a stone that requires more care in wearing than ruby or sapphire. Even so, emeralds are beautiful stones for all types ...

5月の誕生石であるエメラルドの意味、歴史、産地について詳しく学びましょう。

宝石や鉱物の硬度はモース硬度スケールで測定されます。 モース硬度の数字はある1つの鉱物が他の鉱物によって傷つけられることの相対的な容易性または困難性に基づいています。 しかし、モース硬度には紛らわしい面もあります。 モース硬度を代表する鉱物間の硬度の間隔は均等であり ...

誕生石は、楽しくて人気のあるカラフルな方法で宝石の世界へと導いてくれます。性別、年齢、国籍、宗教を問わず、世界中の人々を魅了します。誕生石は、それぞれの宝石特有の秘密 ...

GIA invented the science of grading diamonds with the 4Cs and the International Diamond Grading System ™ – standards used by jewelry professional around the world. So there’s no better place to study ...

Explore the world of diamonds and colored gemstones.

Early diamond hunters in South Africa cared little about absolute age because diamonds were found as alluvial material in riverbeds and beaches, and only where they could be found mattered. Once ...

Manufacture of a solid single-crystal diamond ring is a very complex and challenging process. Once material is removed from the crystal, very fine fractures and imbalanced strain can have severe ...