Brilliance, Windows, and Extinction in Gemstones • Lotus Gemology

A discussion of brilliance, windows and extinction as they relate to the face-up appearance of colored gemstones. Diagrams demonstrate that extinction is largely a function of cut.

Virtually all gemologists are aware of the curved growth lines and gas bubbles in Verneuil (flame-fusion) synthetic corundum, but few understand exactly why they occur and how they are distributed in these stones. This article clarifies these important identifying features.

This article discusses the factors that influence quality and what to look for when buying both jadeite and nephrite. A list of jade auction records is also included.

The history of Thailand's famous relic.

Myanmar's jadeite mines occupy a privileged place, representing the planet's principal source of fine jadeite jade. This article covers the deposits themselves, along with the cutting, grading and trading of jadeite.

An essay on buying gems at the source in Asia, with a discussion of how con men play on the greed of those who believe gems will be cheaper at the mines.

A 2006 mission to remote ruby and spinel localities in Tajikistan.

In search of ruby and sapphire on the lost Isle of Madagascar.

World auction records for ruby, sapphire and spinel.

A look at the geology of Myanmar's Mogok Stone Tract, home to pigeon's blood rubies and so much more…