専門分野で次の段階に進もうとする方も、新しいキャリアを目指す方も、GIA のコースやディプロマプログラムを受講して成功への準備をすることができます。 GIA は、独自の画期的な研究から開発され、業界をリードする ...

Using a multi-step process, Lucent Diamonds has developed a new treatment process for certain natural diamonds that creates colors from pink-purple through red to orangy brown.

View the holiday schedule for all GIA locations worldwide.

Conch "pearls" are calcareous concretions produced by the Queen conch mollusk, Strombus gigas, which is found in various areas of the Caribbean. Although conch"pearls" occur in a range of colors, the ...

The northeastern portion of the state of Minas Gerais, Brazil, contains the world's greatest concentration of complex granitic pegmatites, which are especially noted for the production of gem beryl, ...

PDF versions of the GIA Laboratory-Grown Diamond Reports are available on Report Check. Look for an icon in the upper right hand corner. Once downloaded, the report can be printed for your records.

GIA ensures accurate gemological measurements across its global laboratories through rigorous metrology practices, including systematic instrument calibration, validation from traceable standards, and ...

Blue diffusion-treated sapphires are becoming more prevalent than ever before. The diffusion technique, which involves the addition of color-causing chemicals during heat treatment, results in a thin ...

Several diamonds were treated for the purposes of observation and report with a new laser technique which does not show the typical surface-reaching drill hole.

Gem-quality bright blue to green “Paraíba”-type Cu-bearing tourmaline is now known from deposits in Africa (Nigeria and Mozambique), in addition to three commercial localities in Brazil (in Paraíba ...

Learn more about the GIA Diamond Origin Report service which includes a country of origin opinion for eligible diamonds.

Since late 2007, rubies and sapphires have been mined by hand methods from both eluvial and primary deposits at Winza in central Tanzania.