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Article
GIA Gem Project
Beryl

Chemically pure beryl is colorless, but trace elements give rise to green, blue and pink/red colors.

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Garnet
Article
GIA Gem Project
Garnet

Often thought of as a deep red gemstone, garnet can also be yellow, orange, green or brown – any color except blue.

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Non-nacreous Pen Pearls
Observations on Pearls Reportedly from the Pinnidae Family (Pen Pearls)

Examines the internal structure, chemical composition, and spectroscopic features of 22 pen pearls.

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Article
Paspaley: Inside an Exclusive South Sea Pearl Auction

Fine-quality South Sea cultured pearls can be seen in the world’s fashion capitals, but they all start their journey to market at the auction. GIA offers a rare look inside one of the biggest.

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Article
GIA Gem Project
Various Gems
(Amblygonite - Axinite)

Among the collection assembled by Dr. Edward Gübelin are a number of uncommon gemstones from many worldwide localities.

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Article
GIA Gem Project
Corundum

Ruby and sapphire (usually blue, but also in every other color) have been the most important colored gemstones for several thousand years. Originating historically in southeast and central Asia, and more recently in eastern Africa, these colored varieties of the mineral corundum have been much sought as gems because of their rarity, color and durability. Gem corundum can display asterism and chatoyancy due to the presence of oriented mineral inclusions, and in some cases, a change of color when viewed under different light sources.

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Article
GIA Gem Project
Various Gems (Olivine - Rutile)

Among the collection assembled by Dr. Edward Gübelin are a number of uncommon gemstones from many worldwide localities.

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Article
GIA Gem Project
Various Gems
(Sapphirine - Stibiotantalite)

Among the collection assembled by Dr. Edward Gübelin are a number of uncommon gemstones from many worldwide localities.

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Article
GIA Gem Project
Various Gems (Taaffeite - Zoisite)

Among the collection assembled by Dr. Edward Gübelin are a number of uncommon gemstones from many worldwide localities.

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Article
GIA Gem Project
Various Gems
(Danburite – Humite)

Among the collection assembled by Dr. Edward Gübelin are a number of uncommon gemstones from many worldwide localities.

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