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Indonesian opal cabochons, 6.94 and 3.79 ct.
Opal from West Java, Indonesia

Description of Indonesian opal reportedly from West Java.

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Opal from the Shewa Province, Ethiopia

Opal occurs as nodules in volcanic rocks at a new gem opal locality in the Menz Gishe district of Shewa Province, Ethiopia.

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Worker attaching wax forms
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Shenzhen: The Frontier of China’s Gem and Jewelry Industry

All jewelry professionals are familiar with the city of Shenzhen, a global jewelry manufacturing center and a leader of China’s fast-growing gem and jewelry industry. Join the GIA team as we tour the city and discover more about its leading jewelry brands.

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Underground opal mining in Koroit
Splendor in the Outback: A Visit to Australia’s Opal Fields

Documents a trip to the renowned opal fields of Lightning Ridge, Koroit, Yowah, and Quilpie.

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Petrified wood carvings and cabochons.
Thai-Myanmar Petrified Woods

The properties of petrified woods originating from various localities in Thailand and Myanmar are examined.

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Opal from Querétaro, Mexico: Fluid Inclusion Study

The distinctive orange-to-red “fire" opals from Querétaro have not been found in significant quantities at any other locality.

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Chrysoprase and Prase Opal from Haneti, Central Tanzania
Chrysoprase and Prase Opal from Haneti, Central Tanzania

Commercial quantities of gem-quality chrysoprase and green prase opal (nickel-bearing chalcedony and common opal, respectively) have been recovered from altered serpentinite deposits near Haneti, Tanzania.

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Queensland Boulder Opal

After almost 75 years of inactivity, the deposits of boulder opal in Queensland, Australia, began to attract new interest in the 1960s and 1970s.

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Opals from Opal Butte, Oregon
Opals from Opal Butte, Oregon

Recent mining at Opal Butte in northeastern Oregon has produced a wide variety of large flawless opals.

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Treated Andamooka Matrix Opal
Treated Andamooka Matrix Opal

Matrix opal from Andamooka, in South Australia, is a precious opal-included porous rock that is commonly color enhanced (carbon impregnated) to imitate the highly prized black opal from Lightning Ridge in northern New South Wales, Australia.

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