| The October birthstone is found in a range
of colors that will compliment any wardrobe. Opal offers an abundance of color including
flashes of red, orange, blue and green.
The most rare and valued variety is the black opal, which
displays its flashes of color against a dark background.
Opal is a form of silica, chemically similar to quartz.
Precious opal typically contains from 6 to 10 per cent water. The water content can be as
high as 30%. The color in precious opal is caused by an array of silica spheres
reflecting and interfering with the passage of white light, separating it into the colors
of the spectrum.
The name opal is partly descended
from the Greek word "Opals" meaning "to see a color change". It is a
rather delicate gem which is most often cut in a smooth domed shaped or in a flat disk to
bring out its natural beauty.
Historically, opal symbolized fidelity and assurance
Later opal came to represent religious emotion and prayer.
The primary source of precious white and black opal is
Australia.
Fire opal, typically a milky orange color is found in
Mexico, Brazil, Australia, U.S., and Turkey.
Moh's Hardness: 5.5 - 6.5
Color: white or light gray background with flashes of
color; blue or green background with flashes of color; orange.
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