Articles

A discussion of DRIFTS vs the Beam Condenser FTIR attachment in the testing of pink sapphire. The DRIFTS accessory is generally much better at unmasking heat treatment in ruby and sapphire.

A discussion of the literature of ruby and sapphire (corundum), with particular emphasis on the most collectible books covering ruby and sapphire around the world.

When a red spinel and a tanzanite were submitted for testing, oil was found in the fissures. Removal of the oil resulted in a startling deterioration in clarity.

Solid inclusions have been used by gemologists as a means of determining origin. While there is a great deal of overlap from one source to another, there are also important differences. For example, while apatite has been identified in sapphire from Madagascar, Myanmar and Sri Lanka, apatite has never been identified in sapphire from Kashmir. Thus the purpose of this article is to give a full listing of solid inclusions in gem corundums from around the world, with each occurrence fully referenced. This is provided with the goal of making origin determination of ruby and sapphire more accurate.

A large black star sapphire was brought in for testing. Two large pits on the base were carefully filled with brown dopping varnish. After removal of the varnish with alcohol, it was found that a large portion of the base had been filled with a lead glass.

The word "jade" often evokes the green jadeite used in jewelry. However, some of the most valuable jade in China is not this green jadeite, but in the creamy "mutton fat" carved nephrite from Hetian, Xinjiang province. In the past, many carvings touched upon familiar motifs like dragons or religious symbols, while in recent decades there has been a revolution of carving, with artists incorporating modern themes and styles into their work. Lin Tze-Chuan, an influential collector and patron of many jade carvers, is considered by many to be the father of Chinese contemporary jade carving. Here he discusses the changing world of jade carving and what he looks for when commissioning new work.

A discussion of the literature of jade, with particular emphasis on the most collectable books covering both Chinese jade and jade around the world.

The world sapphire market has changed dramatically in the past 40 years. The authors review the famous sources of the past and look at the current situation in sapphire around the globe.

How does one go about choosing a good gem testing lab? The gemologists at Lotus Gemology provide the following guide to help customers make the best decisions when choosing a good gem testing lab.

To the jeweler, spinel is famous for its vivid colors. But for the gemologist, this gem is unlike any other. Its extreme hardness allows a fine polish. Couple this with single refraction, which eliminates the image blurring found in most other gems, and a varied landscape of inclusion subjects, and the result is an unparalleled canvas of delight for the photomicrographic artist.