Search Results

Two Notable Color-Change Garnets

Carol M. Stockton, June 1, 1982

The gemological properties and chemical compositions of two unusual color-change garnets are reviewed.

This 2.11 ct octagonal mixed-cut spessartine displays a color-change phenomenon.

Color-Change Spessartine Garnet: A First Report

Heidi Breitzmann, Ziyin Sun, and Aaron C. Palke, August 15, 2019

The Carlsbad laboratory encounters a unique spessartine garnet that displays a strong color change from dark green to dark red.

Garnets, Sapphires, Opals, and Tarnish on High-Purity Gold

Duncan Pay, February 1, 2016

An overview of the Winter 2015 Gems & Gemology content.

A Proposed New Classification for Gem-Quality Garnets

Carol M. Stockton and D. Vincent Manson, December 1, 1985

Eight garnet species are defined and methods of identification are described.

Pyrope-Spessartine Garnets with Unusual Color Behavior

D. Vincent Manson and Carol M. Stockton, December 1, 1984

Unusual color-change garnets.

Article

Pyrope Garnet and Montana Sapphires Highlight Winter 2015 G&G

Russell Shor, February 1, 2016

G&G Brief presents an overview of the content of the Winter 2015 issue of Gems & Gemology.

Cat’s-eye phenomenon seen in a large brownish yellow andradite.

Cat’s-Eye Andradite

Nicole Ahline, October 22, 2020

Fine needle inclusions create a striking cat’s-eye effect in a rare brownish yellow andradite garnet.

The Andradites of San Benito County, California

Tedd Payne, September 1, 1981

Mines in San Benito County, California, produce andradite in various colors; some are chatoyant.

Figure 1. Iridescent andradite samples (25 ct and 125 ct) from the Lindong area of Inner Mongolia, China. As shown in the left photo, sample G-1 displays iridescence on the (211) plane but not on the (110) plane. Photos by Jiuchang Yang.

A Newly Discovered Iridescent Andradite from Inner Mongolia, China

Jiuchang Yang, Quanli Chen, Fengshun Xu, Yan Li, and Xianyu Liu, November 3, 2023

The first report of iridescent andradite from China.

Gemstones with Alexandrite Effect

E. Gübelin and K. Schmetzer, December 1, 1982

The term "alexandrite effect" refers to the apparent change of color in certain minerals from blue-green or greenish violet in daylight to red or reddish violet in incandescent light.

Types

Topics

Topics

Gemstones

Gemstones

Search Results

Types

Topics

Topics

Gemstones

Gemstones

You Might Also Like

Learn About Education On Campus and Online

GIA NextGem™Diamond Trainingfor Retail

Explore GIA Laboratory Promotional Offers

Shop theGIA Store

GIA NextGem™
Diamond Training
for Retail

Shop the
GIA Store