Gain in-depth knowledge about the multitude of colored stones sold in today’s market. Topics include which gems are commercially important and why, the differences in gem values and shifting supply ...

GIA is proud to provide the most comprehensive research in the industry with a world-renowned field gemology team and a dedication to acquiring colored stones directly from the source. Our ...

The GIA Laboratory-Grown Diamond Report includes full quality assessment with a plotted clarity diagram. Color and clarity specification are described on the same scale as the GIA Diamond Grading ...

3月の2つの誕生石であるアクアマリンとブラッドストーンは全く異なって見えますが、幸福をもたらすという共通の効果を持っています。アクアマリンの誕生石からは海の色が思い浮かびます。

11月生まれの方は、2つの美しい誕生石、トパーズとシトリンからお好きなものを選ぶことができます。トパーズには虹のように様々な色があります。そしてシトリンには魅力的な黄色や ...

Figure 1. These coral (left) and gastropod (right) fossils are pseudomorphs in demantoid garnet from Ambanja, Madagascar. The coral measures 1.5 × 1 cm. Photo by Pierre-Yves Chatagnier. In 2010, two ...

Two new deposits of Cu-bearing tourmaline have been found in Paraíba State, Brazil, not far from the original source at Mina da Batalha. The Glorious mine has produced a limited amount of gem-quality ...

3.28カラットのパライバ産トルマリンの、この鮮やかなバイオレットがかった青の色相は、最高級のサファイアに匹敵する。 このトルマリンの希少性から、1カラットあたりの価格もまた ...

高級品部門で何年も働いた後、レオは宝石鑑定士の卒業証書を取得しました。 優れた学業成績と関連した実務経験をもつ彼は、理想的なGIA講師です。

Figure 1. The sparsely populated high desert of eastern Oregon is home to three localities producing natural copper-bearing labradorite feldspar. In this view of Lake County’s Dust Devil mine, the ...

A 43-carat alexandrite in the collection of the British Museum. Abundant alexandrite deposits were first discovered in 1830 in Russia’s Ural Mountains. Those first alexandrites were of very fine ...

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