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Synthetic Ruby Overgrowth on Natural Corundum
Article
Analysis of Synthetic Ruby Overgrowth on Corundum

Analysis of synthetic ruby overgrowth on corundum, using analysis of inclusions, UV-Vis-NIR and EDXRF spectroscopy, and LA-ICP-MS.

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Blue sapphires
Article
An In-Depth Gemological Study of Blue Sapphires from Pailin, Cambodia

A report from GIA Laboratory in Bangkok analyzing 68 blue sapphires from Pailin, Cambodia.

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Cambodian-Thai Ruby
Article
A Study of Rubies from Cambodia and Thailand

A report from the GIA Laboratory in Bangkok analyzing 41 Cambodian-Thai rubies.

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Four Pinctada maculata bead-cultured blister pearls
Article
Pinctada maculata (Pipi) Bead-Cultured Blister Pearls Attached to Their Shells

A study on four Pinctada maculata cultured blister pearls originating from Penrhyn Island.

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Rough and cut sapphires
Article
A Study of Sapphire from Chanthaburi, Thailand and its Gemological Characteristics

A report from the GIA Laboratory in Bangkok presents their findings on 59 blue sapphire samples obtained from a miner in the Khao Ploy Waen area, Chanthaburi.

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Blue Sapphires
Article
An In-Depth Gemological Study of Blue Sapphires from the Baw Mar Mine (Mogok, Myanmar)

GIA field gemologists visited Baw Mar operations in 2013, 2014, and 2015. In this study, we analyzed samples collected during two separate expeditions.

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Sapphire
Article
Sapphires from the Gem Rush Bemainty area, Ambatondrazaka (Madagascar)

The discovery of many fine quality sapphires in this area is opening a new chapter in the conflict between conservation and gem mining in northeastern Madagascar.

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Article
Atypical “Beading” in the Production of Cultured Pearls from Australian Pinctada Maxima

In 2011, the authors began to see cases of low-quality natural pearls being used as unconventional “beads” for cultured nacre growth.

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Unheated faceted and rough rubies weighing from 0.9 to 5.4 carats from Niassa
Article
Rubies Reportedly from Mozambique

Attractive new rubies reportedly from northern Mozambique have begun to appear on the Thai gem market. The stones resemble rubies from Winza, Tanzania, but this study shows they can be distinguished by microscopic examination.

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This 2.14 ct “Fancy red” oval-cut diamond was produced through a multi-step treatment process.
Article
Treated Fancy Red Diamond

Examines a 2.14 ct oval-cut diamond, graded as Fancy red, whose red color was produced through a combination of high-presssure, high-temperature (HPHT) treatment and irradiation plus annealing.

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