Examines the current available means of determining the geographic origin of gem-quality diamond, which are based largely on trace element and isotopic characteristics. For now, no method exists for determining the provenance of a random individual diamond.

A comprehensive look at the gemological features and advanced analysis of blue and fancy-color sapphire from the agricultural area of Muling, China.

Explores the use of gem materials as pigments in works of art, from the earliest cave paintings to the modern era.

A detailed spectroscopic investigation of the color of pink spinel reportedly from the Kuh-i-Lal deposit in the Pamir Mountains of Tajikistan.