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Tourmaline History and Lore

Somewhere in Brazil in the 1500s, a Spanish conquistador washed the dirt from a green tourmaline crystal and confused the vibrant gem with emerald. His confusion lived on until scientists recognized tourmaline as a distinct mineral species in the 1800s.

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Pearl History and Lore

People have coveted natural pearls as symbols of wealth and status for thousands of years.

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Amethyst History and Lore

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Alexandrite Care and Cleaning Guide

Learn about alexandrite's durability and how to care for your alexandrite jewelry.

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G&G Publication Info

This document provides the publication information for Gems & Gemology

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Distinguishing Heated Spinels from Unheated Natural Spinels and from Synthetic Spinels

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Analysis of HPHT-Treated Diamonds Using Fluorescence Observations

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GIA's Gubelin Gem Project: Corundum

几千年来,红宝石和蓝宝石(通常为蓝色,有时也有各种其他颜色)一直都是最重要的有色宝石。这些刚玉族矿物包含各种颜色类别,历史上原产于东南亚和中亚地区,如今由于它们珍贵稀有、色彩瑰丽、坚硬耐磨,已经成为备受追捧的宝石。由于有向分布的矿物内含物,刚玉可以呈现出星光和猫睛光,在不同的光源下观察时,有时还会变色。

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Tourmaline Care and Cleaning Guide

Learn about tourmaline's durability and how to care for your tourmaline jewelry.

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Alexandrite Description

Alexandrite, with its chameleon-like qualities, is a rare variety of the mineral chrysoberyl. Its color can be a lovely green in daylight or fluorescent light, changing to brownish or purplish red in the incandescent light from a lamp or candle flame.

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Alexandrite History and Lore

The gem was named after the young Alexander II, heir apparent to the throne. It caught the country’s attention because its red and green colors mirrored the Imperial Russian flag.

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Alexandrite Quality Factors

Learn about the factors that make alexandrite so desirable.

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