Professional Jeweler Archive: Behind the Hazy Look

May 2000

Gemstones & Pearls: Gemology

Behind the Hazy Look

The third installment of our series on inclusions makes it very clear that some sapphires are not

Some natural blue sapphires have a limpid or watery look, while others are singled out as hazy or having a sleepy appearance.

The difference in the appearance of sapphire lies in the presence (or lack) of minuscule, fibrous inclusions of another mineral.

In top qualities of the highly coveted sapphires from Kashmir, for example, inclusions are often so small they’re barely visible to the naked eye. Because of their number, however, they affect the transparency, softly blurring or softening the overall color. These sapphires generally have a uniform body color.

Some sapphires from Madagascar show similar characteristics to those of their cousins from Kashmir, including the haziness and blurring. A macrophoto of this Madagascar sapphire (below right), for example, reveals a soft, pastel blue. Through the microscope at 35X, you see a nest of rutile silk, a form of titanium oxide in the sapphire. This suggests the sapphire has not been heated, a treatment that would have dissolved the rutile silk and improved its transparency.

This beautiful sapphire is for a buyer who wants a natural gem with an air of mystery.

– by Robert Weldon, G.G.

Above: Cushion-cut sapphire from Madagascar. Courtesy of Allerton Cushman & Co., Sun Valley, ID.

Right: Fine rutile silk in the same sapphire is identified at about 35X.

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