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

The Capão mine is one of the oldest and most productive fully mechanized Imperial topaz mines in the historic Ouro Preto area of Minas Gerais, Brazil.

Gem-quality enstatite, cordierite, kornerupine, and scapolite with unusual properties have been recovered from alluvial deposits in the region of Embilipitiya, Sri Lanka.

Among the most difficult gems to identify are those that are black and opaque (or nearly so).

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

Opal occurs as nodules in volcanic rocks at a new gem opal locality in the Menz Gishe district of Shewa Province, Ethiopia.

Demantoid, green andradite garnet, was discovered in the Central Ural Mountains of Russia in the mid-19th century.

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

A compilation of gem news from around the world, covering topics such as localities, unusual gem materials, market news, new products, discoveries, jewelry manufacturing techniques, and industry trends.

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).

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

Exploration of a chart designed to give jewelers and gemologists a practical guide to identifying synthetic diamonds as they enter the jewelry trade.

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

One of the most interesting of the commercially available Czochralski pulled synthetic corundums is pink “Ti-sapphire.”

A find of new gem garnets has been made in contact metamorphic deposits in the Republic of Mali, western Africa.

This article illustrates the various features in filled diamonds and explores the best techniques for examining them.

The emeralds of the Ural Mountains, in what is now called the Russian Federation, have been known for more than 160 years.

The history of Baja California has been closely tied to the exploitation of pearls since the 16th century.

Yogo Gulch, discovered more than 100 years ago, is one of four major sapphire-producing areas in Montana, United States.

Large quantities of rubies—both rough and faceted—from a commercially important new source in Myanmar (Burma) have been available on the Bangkok market since 1992.