Winter 2011 G&G Lab Notes
This section, from the Winter 2011 issue of Gems & Gemmology, is a compilation of interesting finds from GIA’s laboratories.
Spectral Reflectance and Fluorescence Characteristics of Natural-Colour and Heat-Treated “Golden” South Sea Cultured Pearls
A comparison study was made between the yellow and white nacre of the gold-lipped Pinctada maxima oyster shell and 65 yellow cultured pearls.
Continuity and Change in Chinese Freshwater Pearl Culture
Farmers have experimented with bead nucleation, but until recently the methods tried did not produce the quantity or quality necessary for economic success.
Natural pearls from Australian Pinctada maxima
The fascinating and colourful history of natural pearling in Australian waters.
Cultured Pearls from the Gulf of California, Mexico
Black pearls have been found in Mexico’s Gulf of California since the area was settled more than 2,000 years ago.
Culture Abalone Blister Pearls from New Zealand
The successful culturing of abalone pearls has been known since French scientist Louis Boutan’s experimentation in the late 1890s, but commercial production has only been achieved in recent decades.
Identification of “Chocolate Pearls” Treated by Ballerina Pearl Co.
Treated cultured pearls with a “chocolate” colouration have entered the market from several sources.
Polynesian Black Pearls
Historically, natural black pearls have been one of the rarest and most exotic of gem materials.
Freshwater Pearls of North America
The American freshwater pearl industry and its new entry, the freshwater cultured pearl.
Cultured 3/4 Blister Pearls
This article describes the method of culturing these "pearls" as well as the differences between this material and 3/4 South Sea cultured pearls or assembled cultured blister pearls (Mabe pearls).