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A row of five low-quality bead cultured pearls.
Article
A Study on Improving the Surface Appearance of Low-Quality Pinctada maxima Bead Cultured Pearls

In this study, the Bangkok laboratory examined five low-quality bead cultured pearls sourced directly from a local pearl factory and characterised their features before and after processing.

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A white and purple pearl sitting in half of its shell.
Article
Clam Chowder with a Side of Pearl

Recently, GIA’s laboratory in New York had the opportunity to examine a fascinating pearl find and hear about an even more fascinating story.

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Faceted blue zircons
Reversible Colour Modification of Blue Zircon by Long-Wave Ultraviolet Radiation

Determines whether blue zircon, inadvertently altered to brown by exposure to long-wave UV radiation, can be restored to its original colour through the use of incandescent light.

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Vanadium and Chromium-Bearing Pink Pyrope Garnet: Characterisation and Quantitative Colorimetric Analysis

This type of pink pyrope garnet, believed to have been mined in Tanzania, shows a distinct colour-change phenomenon resulting from its unique chemical composition.

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A face-up view of a cushion cut diamond with blue color.
Article
Gems & Gemology’s 7 Most Unusual Encounters from 2019

Check out some of the most interesting and unusual diamonds and coloured stones submitted to GIA’s laboratories in 2019.

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A row of various shaped cut and polished pink diamonds.
Article
Why are Pink Diamonds Pink? GIA Researchers Dive Deep into their Crystal Structure

GIA researchers analysed more than 90,000 natural pink diamonds to better understand how these rare and beautiful diamonds formed and got their colour.

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An oval shaped 33.40 ct white Australian opal and diamond pendant/brooch set in platinum.
Article
The Enigmatic Gemstone: Opal’s Playful Dance with Light

Opal’s play-of-colour is a lyrical dance: sometimes a grand jeté of bold, broad flashes of colour or smaller, quicksteps of pinpoint flashes.

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A pile of rough diamonds.
Article
US Government to Industry: Know Your Supply Chain; De Beers and Alrosa Cut Rough Sales

De Beers and Alrosa slashed rough diamond sales after ABN AMRO’s says it will no longer finance rough purchases for goods that can’t be cut profitably.

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Six different shaped red and pink diamonds lined up in a row.
Article
Bank Suspends Credit for ‘Unprofitable’ Rough Diamonds

De Beers and Alrosa slashed rough diamond sales after ABN AMRO’s says it will no longer finance rough purchases for goods that can’t be cut profitably.

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People meet and mingle at the entrance to the JCK Show.
Article
Headwinds Slow 2019 Vegas Business, Lab-grown Diamonds Proliferate

Decent demand for finished jewellery, but less for loose gems. Plus: Lab-grown diamonds and responsible, sustainable business practices.

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