Baroque-Era Rose Cuts of Colored Stones: Highlights from the Second Half of the Seventeenth Century

Offers a systematic evaluation of rose cuts produced for various colored stones in the latter seventeenth century, based on the examination of rare artifacts that belonged to the archbishops and prince-electors of Trier and Cologne.

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Unusual Absorption in a Blue Flux-Grown Synthetic Sapphire

The Bangkok lab identified unexpected characteristics in a flux-grown synthetic sapphire.

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Largest CVD Laboratory-Grown Diamond Submitted to GIA

Progress in creating laboratory-grown CVD diamonds allows for larger sizes, including the largest yet seen at the Carlsbad lab.

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Large Type IIa Diamond from Arkansas, USA

The GIA lab in Carlsbad recently had the opportunity to examine a truly “all-American” diamond.

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Mineral Inclusions in Sapphire from Basaltic Terranes in Southern Vietnam: Indicator of Formation Model

Proposes a formation model for sapphire from the main deposits in southern Vietnam based on the chemical composition of their mineral inclusions.

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Low-Temperature Heat Treatment of Pink Sapphires from Ilakaka, Madagascar

Studies the effects of low-temperature heat treatment on inclusions in this gem material, as well as the use of FTIR spectroscopy to detect the treatment.

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Fluorescence Characteristics of Blue Amber from the Dominican Republic, Mexico, and Myanmar

Presents a combination of observational and spectroscopic means to separate the three main geographic localities for blue amber, which shows very strong blue fluorescence under sunlight or D65 illumination.

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Artificial Glass Imitating a Paraíba Tourmaline

A creative imitation using fused bluish green glass with copper platelets poses as Paraíba tourmaline.

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What Have Diamond Ages Taught Us?

Diamond ages offer insight into continent evolution spanning billions of years.

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Rhodium-Plated Iron Meteorites

The annual Tucson Gem and Mineral Show has been a reliable source for the niche and the unusual, as seen with the rhodium-plated iron meteorites acquired by author BL at the 22nd Street Show in February 2020.

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Snowflake Inclusions in Mong Hsu Ruby

A holiday snowflake scene in a treated Mong Hsu ruby surprises and delights a gemologist in the Bangkok lab.

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New Emerald Locality in Southern California

Located about 60 miles east of San Diego, a new emerald deposit has been discovered in the Julian Mining District.

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Uncommon Inclusion of Lazurite in Ruby from Mogok, Myanmar

A parcel of small rubies was received for identification at the S Gemmological Institute (SGI) gem lab in Yangon, Myanmar.

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Pink Sapphires from Madagascar, Rose-Cut Colored Stones from the Baroque Era, Separating Blue Amber Localities, and More…

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Winter 2020 G&G Publication Information

This document provides the publication information for Gems & Gemology

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