
Kimberlites: Earth’s Diamond Delivery System
Examines the basic characteristics of kimberlites and their relationship with diamonds.

A Pearl Identification Challenge
Two pearls presented a unique challenge, as testing at three different gemological laboratories could not conclusively identify them as natural or cultured, determine a freshwater or saltwater growth environment, or specify the producing mollusk.

Black Nephrite Jade from Guangxi, Southern China
Characterizes black nephrite from a deposit in the Guangxi region that appears to be part of a large-scale jade formation belt in southern China.

Madagascar Sapphire: Low-Temperature Heat Treatment Experiments
Shows how the color of Madagascar sapphire is lightened with heating to relatively low temperatures below 1350°C.

A Decade of Ruby from Mozambique: A Review (英語)
Reviews the mining history, market impact, and properties of ruby from northern Mozambique near Montepuez, now the world’s most productive source.

Tagua Nut as a Sustainable Botanical Alternative for Ivory
Jewelry designer Alexandra Mor uses sustainable alternatives for elephant ivory.

The Effect of Low-Temperature Heat Treatment on Pink Sapphire
Twelve pink sapphires undergo low-temperature heat treatment and reveal a correlation with the 3232 cm-1 FTIR peak.

A Special Type of Trapiche Quartz
Three incomplete trapiche quartz make up this interesting sample.

Gemological and Chemical Characteristics of Natural Freshwater Pearls from the Mississippi River System
GIA had the unique opportunity to study the gemological and chemical characteristics of 854 natural freshwater pearls from the Mississippi River system.

Dive Into Summer: Mozambique Ruby, Madagascar Sapphire, and Black Nephrite from China, Plus an Opal Inclusions Chart
An overview of the Summer 2019 Gems & Gemology content.

Gem Art of the Taj Mahal, Fancy White and Black Diamonds, and Unique Inclusions in Thai Corundum
An overview of the Fall 2019 Gems & Gemology content.

Euhedral Phantom Sapphire in Sapphire
A phantom sapphire crystal within a host sapphire crystal was recently examined at GIA’s Carlsbad laboratory.

同窓生の生涯にわたる旅:ジュエリーユニコーンを探し求めて
Alan Nachtは、家族の遺産であるBernard Nacht & Co.を継承し、一生忘れられない見事なジュエリーをこれからも探し続けます。


A Tropical Paradise of Ocean-Inspired Jewelry and Gemstones


Chow Tai Fook(周大福)、GIAでブロックチェーン・イニシアティブを拡大
Chow Tai Fook(周大福)とGIAは、ダイヤモンドの旅とグレーディング情報を一箇所に記録する安全なデジタルブロックチェーンレポートを提供します。



ハリウッドの宝飾品:スターを輝かせたアクセサリーとジュエリー
Kazanjian Foundation(カザンジャン財団)から貸し出された「ハリウッドの宝飾品」はハリウッドのスターに関連する幾つかのジュエリーやアクセサリーを展示しています。

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