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HPHT-treated blue diamond (left) with ragged-looking graphitization around an inclusion (center) and high-order interference colors with crossed-polarizing filters (right).
Large HPHT-Treated Blue Type IIb Diamond

Properties of, and theories on color zoning exhibited by, the largest HPHT-treated blue diamond graded by GIA.

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These rubies were determined to be glass filled, partly due to the use of the DiamondView.
Separating Glass-Filled Rubies Using the DiamondView

The DiamondView instrument is able to identify glass as the filler in a pair of heart-shaped rubies.

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Two white jade bracelets with dark color patches.
Nephrite Bracelet with Filled Cavity

A jade bracelet contains unusual fillers, used to create a smooth surface.

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The wax-impregnated bangle (left) showed bluish fluorescence under long-wave UV.
Strong Fluorescence in B-Jade Impregnated with Wax

A bangle is an example of the misconception that B jade is only impregnated by resin, when in fact wax-impregnated jadeite is also considered B-jade.

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Colombian Emerald Industry: The New Generation

Luis Gabriel Angarita and Edwin Molina share their experiences and perspective on the Colombian emerald industry.

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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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This fancy deep green-blue diamond was treated in a multi-step process.
Irradiated and Annealed Blue Type Ia Diamond

Examination shows that a diamond was subjected to a multi-step process in order to introduce a blue color.

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Brown-orange treated CVD-grown synthetic diamond.
Fancy Deep Brown-Orange CVD Synthetic Diamond

A CVD-grown diamond shows an unexpected treatment-caused color.

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Diamond before and after filling large fractures.
Fracture-Filled Diamond with "Rainbow" Flash Effect

The material used to fill a large fracture in a diamond yields an unexpected iridescence under two different illuminations.

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Small unheated spinel and sapphire exhibited by Madagascar Imports
Unheated and Unusual Colors

Margit Thorndal of Madagascar Imports offers her perspective on the colored stone market.

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