The Hope diamond, the Dresden Green, the Idol’s Eye, the Portuguese Diamond and the Moussaieff Red – these famous diamonds are spectacularly beautiful jewels that have been admired for centuries. An ...

During an expedition to China, a GIA team was introduced to the largest jadeite boulder being carved. This amazing blend of nature’s beauty and man’s artistry is an ongoing project to which master ...

At the earth’s surface, graphite is the stable crystalline form of carbon, with a density of 2.26 g/cm 3. Diamond is a much more compact form of carbon, with a density of 3.52 g/cm 3, 56% higher than ...

Once a gem is submitted: Your name or store info is removed, so analysis is completely unbiased. Every gem, whether from a local jeweler or a globally recognized brand, is evaluated using the same ...

Your name or store info is removed so grading is completely unbiased. Every pearl or pearl strand, whether from a local jeweler or a globally recognized brand, is evaluated using the same rigorous, ...

2024年に予定されているGIAキャリアフェアはありません。 GIAは、優秀な人材を求めているジュエリー業界の雇用者だけでなく、学生にも提供するサポートや機会を継続的に強化することをお ...

Two pearls presented a unique challenge, as testing at three different gemological laboratories could not conclusively identify them as natural or cultured, determine a freshwater or saltwater growth ...

Al Gilbertson, a GIA researcher, says if you think of a diamond like “a series of mirrors reflecting its environment,” it can help you understand how light and location can change the way your diamond ...

Courtesy of Tom Dodge CollectionThis 54.32-carat fire obsidian displays vibrant colors caused by thin-film interference. Light reflects off nanoscale layers of magnetite within the stone, and the ...

The fee for the GIA Laboratory-Grown Diamond Quality Assessment is US$15 per carat, with a minimum fee of $15. Submissions that do not meet the minimum criteria for assessment will be charged a US$5 ...

The Motswedi diamond weighed 2,488.32 carats (approximately 1.10 pounds!) upon arrival at GIA, along with 11 smaller fragments that had broken off, weighing a total of 1.50 carats. Two larger pieces ...

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