An overview of Australia's recent significance in the production of blue sapphire.

A further article exploring tourmaline mines in another part of Minas Gerais.

A history of pearls in jewelry and fashions through the ages.

The unusual effects of dispersion and twinning produced by a calcite gemstone.

The unique mineralogical and gemological character of gem-quality red beryl from Utah.

Unusual color-change garnets.

An examination and analysis of 15 natural rubies with glass-filled cavities.

The American freshwater pearl industry and its new entry, the freshwater cultured pearl.

First in a series, this article reviews the exploration for gemstones and mining methods in Minas Gerais, Brazil.

A survey of the current gemological knowledge of pegmatites, including the gem varieties aquamarine, tourmaline, and topaz.

Similarities between natural spinels — with intense blue color — and synthetic material, have led to difficulties in the recognition of the natural stones by traditional methods.

The author has uncovered many ancient references to the simulation or enhancement of gemstones.

The properties of a novel gemological imitation, cobalt glass.

A review of the history of this area, its geology, and the mining methods that have predominated.

This article focuses on Colombian emeralds and gives a detailed explanation of the oiling process as observed by the author.

A report on the new synthetic ruby trade-named Ramaura.

The history of the Kashmir mines, the beautiful sapphires found there, and the outlook for the future.

This article examines the history of the Ouro Preto district as well as the geology of the area and occurrence of the topaz.

An overview of the jewelry produced during the Art Deco period.

The term "alexandrite effect" refers to the apparent change of color in certain minerals from blue-green or greenish violet in daylight to red or reddish violet in incandescent light.