Research Article Search Results

A mathematical model which can analyze how appearance factors depend on proportions.

Natural and synthetic gem rubies can be separated on the basis of their trace-element chemistry.

This article reviews the rise of the modern diamond cutting industry in India and its impact on the world diamond trade.

Synthetic emeralds grown hydrothermally in an alkali-free, chlorine-bearing solution have been manufactured in Guilin, China, since 1987.

Examination of 51 colorless to near-colorless synthetic diamonds from all known sources of production confirms that they can be distinguished from similar-appearing natural diamonds on the basis of their gemological properties.

Ruby crystals from Southeast Asia with a fixed six-rayed star, similar in effect to trapiche emeralds from Colombia, are described.

Two instruments have been developed at De Beers DTC Research Centre, Maidenhead, to distinguish synthetic diamonds from natural diamonds.

Since 1993, large amounts of gem-quality sapphires from the Andranondambo region of southern Madagascar have entered the international gem market.

This article explores the mining developments and new diamond occurrences in Africa that led to many of the key concepts in modern geology.

A new type of Russian hydrothermal synthetic emerald is produced by seeded growth in steel autoclaves without noble-metal inserts; the seed slices have been cut parallel to a face of the second-order hexagonal dipyramid s (1121).

For more than 100 years, Africa has produced large commercial quantities of diamonds and important individual stones.