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Figure 1. The color zoning in this 3.57 ct almandine garnet creates a cross structure that forms three-arm trapiche patterns at every intersecting point of the crystal. Photo by Le Ngoc Nang.

Trapiche Garnet from Vietnam

Le Ngoc Nang, Ho Nguyen Tri Man, and Pham Minh Tien, January 26, 2024

A rare occurrence of 14 trapiche patterns is observed in a garnet sample from Vietnam.

$A purplish pink xenomorphic octahedral garnet crystal seen in a diamond. Note the trigons on the upper right octahedral face and stress fractures around the intersections of the crystal faces. Photomicrograph by Britni LeCroy; field of view 1.26 mm.$

Xenomorphic Garnet in Diamond

Britni LeCroy and Virginia Schwartz, May 23, 2023

A purplish pink garnet crystal formed in the same octahedral shape as its diamond host.

Figure 1. Three near-colorless transparent grossular garnet tablets with black inclusions arranged in snowflake-like patterns: 0.46, 0.68, and 1.00 ct, respectively. Photo by Shunsuke Nagai.

Trapiche Pattern Formation of Grossular Garnets

Taku Okada and Kazuko Saruwatari, November 17, 2025

GIA’s Tokyo laboratory examines three grossular garnets displaying six-rayed black inclusions arranged in a snowflake-like pattern.

Spessartine Garnet from Ramona, San Diego County, California

Brendan M. Laurs, Kimberly Knox, December 1, 2001

For most of the 20th century, the principal source of fine spessartine was the area around the Little Three mine near the town of Ramona in southern California.

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.

This “snail” inclusion was viewed through the upper half facet of a 4.00 ct near-colorless diamond. The purple-red “shell” was identified as pyrope garnet, while the green “body” was determined to be diopside. Photomicrograph by Christopher Vendrell; field of view 1.99 mm.

“Snail” in Diamond

Christopher Vendrell, August 4, 2023

A combination of pyrope garnet and diopside inclusions is reminiscent of a snail in a near-colorless diamond.

A large yellow cushion cut diamond pendant is partially framed with marquis cut diamonds and hangs from a necklace of mixed cut diamonds.

Article

Yellow Gemstones: Can You Identify Them?

Sharon Bohannon, March 9, 2020

Don’t judge a yellow gem by its color alone. A variety of gemstones also come in shades of yellow, from diamonds to citrine to garnets.

Demantoid from Val Malenco, Italy: Review and Update

Ilaria Adamo, Rosangela Bocchio, Valeria Diella, Alessandro Pavese, Pietro Vignola, Loredana Prosperi, and Valentina Palanza, February 9, 2009

New data are presented for demantoid from Val Malenco, Italy, as obtained by classical gemological methods.

Abstracts; Fall 1991

Dona M. Dirlam

This article, from the Fall 1991 issue of Gems & Gemology, is a compilation of abstracts of important gemology-related articles published outside of Gems & Gemology.

Figure 1. Mantle eclogite xenolith (2.8 cm in longest dimension) consisting of clinopyroxene (green) and garnet (red-orange), with a partially exposed octahedral diamond. Photo by Annie Haynes. Gift of Mark Mauthner, GIA Museum no. 37511.

Diamondiferous Mantle Eclogite: Diamond Surface Features Reveal a Multistage Geologic History

Matthew F. Hardman and Mei Yan Lai, November 3, 2023

Reports on the analysis of a mantle eclogite xenolith with a partially exposed octahedral diamond.

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