An unusual assembled stone is examined at GIA’s New York lab.

Lotus Gemology receives submissions of star stones on a regular basis, so when we first saw the specimen shown here, it appeared to be one among many of our usual stones to test.

Rare pearls, along with their shell, are studied in the Hong Kong lab.

The first known group of color-change gem-quality chrome grossular garnet, reportedly from Ethiopia, is examined in GIA’s Carlsbad lab.

A project coordinated by GIA and the NGO Pact provides a valuable educational tool to women miners in Tanzania.

A look at the color zoning exhibited by the largest HPHT-treated blue diamond graded by GIA.

A black star sapphire produced from eastern Thailand, showing both golden and silver rays, is studied at GIA’s Bangkok lab.

Aesthetically pleasing inclusions are found in topaz from Pakistan’s Shigar Valley.

Gold: Vortex, Virtues, and Values was hosted by Initiatives in Art and Culture (IAC) at Bohemian National Hall in New York City, April 12–13. Now in its eighth year, the conference has become an annual industry gathering for those looking to evaluate the market, discover exceptional work, and discuss key gold-related issues.

Projects developed by the GemHub to benefit miners, cutters, and others involved in the gem and jewelry industry.

For the first time, wurtzite is found as an inclusion in gem material.

Irradiated CVD-grown diamonds are examined in the Carlsbad lab.

Over the last decade, the production methods used to create synthetic diamond melee have improved substantially, along with the quality of the specimens themselves.

Crassostrea virginica, the so-called Eastern or American oyster, is a commercial seafood widely distributed along the east coast of the United States to the Gulf of Mexico.

A diamond examined in the Carlsbad lab shows chameleon coloring in an unusual pattern.

A Medusa quartz from Paraíba, Brazil, hosts a surprising inclusion.

全5部の連載記事『カラー宝石（ダイヤモンド以外）の価値要因、デザイン、カットの品質』の第1部。この記事は、カラー宝石の価格に影響を与える主な価値要因について説明します。

Part 4 of 5 in the series "Value Factors, Design, and Cut Quality of Colored Gemstones (Non-Diamond)" digs deeper into cutters’ choices and explores additional factors used in the trade to assess relative value.