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An early black and white photo that shows deep trenches dug into the ground in the search for diamonds. Ladders and ropes help the miners excavate and traverse the mine.
Article
Historical Reading: The Diamond Fields of South Africa: Part 1 (1868-1893)

The discovery of diamonds in South Africa in early 1867 marked the start of an historic period of diamond exploration.

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Article
A Sunstone Odyssey, Part 1: The Ponderosa

The first of a three-part series exploring Oregon’s state gem reports on a July 2013 visit to the Ponderosa mine, a prolific sunstone source surrounded by majestic ponderosas.

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Large sunstone rough from the Ponderosa mine in Oregon
Ponderosa Sunstone Update

John Woodmark provides an update on the Ponderosa sunstone mine in Oregon.

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Recent production of turquoise from Polk County, Arkansas
Turquoise from Western Arkansas

A report on turquoise from the only known U.S. deposit outside of the Southwest.

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Solution-Generated Pink Color Surrounding Growth Tubes and Cracks in Blue to Blue-Green Copper-Bearing Tourmalines
Solution-Generated Pink Color Surrounding Growth Tubes and Cracks in Blue to Blue-Green Copper-Bearing Tourmalines from Mozambique

Several transparent, faceted, blue to blue-green copper-bearing tourmalines containing growth tubes and cracks surrounded by sleeves of pink color were examined for this report.

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Expedition to the Cruzeiro Tourmaline Mine in Minas Gerais, Brazil

Journey with us to Brazil for a visit to one of the world’s most prolific tourmaline mines. You’ll also hear a highly captivating story of family success through perseverance.

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From Brazil to China: The Journey of Rubellite Tourmaline

After documenting tourmaline production at the famous Cruzeiro mine in Brazil, GIA takes you to China, where you can witness the cutting of these stones for entry into the hottest tourmaline market in the world.

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Rough blue spinel crystals from Luc Yen
Blue Spinel from the Luc Yen District of Vietnam

Offers geological context and gemological characterization of this increasingly popular vivid blue spinel from northeast Vietnam.

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Peridot from Sardinia, Italy
Characterization of Peridot from Sardinia, Italy

Gem-quality peridot is occasionally found as mantle xenoliths within basalts near Pozzomaggiore.

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 Hand holding tube-shaped boulder opal
Article
Queensland Opal Fields: Home of the Unique Australian Boulder Opal

Boulder opal is becoming more and more popular. Australia’s central Queensland is the home of more than a dozen of sources of this stone. Come with GIA field gemologists to find out more about this unique gem.

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