Opal is October’s Birthstone
HISTORY:
Opal is the
official birthstone for the month of October. It is derived from the
Sanskrit word “upala”, meaning valuable stone. The discovery of opals
is ancient and uncertain. It is believed that opals were first mined
around 400 BC in Ethiopia but their popularity didn’t grow until around
100 BC when they were mined in Hungary. Precious opals were discovered
in South Australia, Queensland, and New South Wales, Australia in 1887.
Australia is now the world’s primary source of precious opals. There
is an old idea that opals are bad luck but Queen Victoria’s love of
opals restored their popularity.
OPAL GEMSTONE PROPERTIES:
Opal is an
amorphous form of silica related to quartz, a mineraloid form, not a
mineral. Opals are unique stones that come in a variety of colors, as
well as rainbows of color in one stone. Most precious opals have a white
or nearly colorless base and, in wonderful cases, exhibit sparkles of
color known as play-of-color. Black opals actually have a dark blue or
blue-green base, and opals known as semi-black can have a grayish,
bluish, or greenish base. Opal ranks a 5.5-6 on Mohs’ hardness scale.
CARE INSTRUCTIONS:
Opals should be protected from
chemicals, high heat, prolonged direct sunlight, and any kind of oil or
grease. Because opals are 5 to 10 percent water, it is natural they
might dry out and craze (small hairline cracks) after a lifetime set in a
piece of jewelry. They should not be stored in dry, air-tight
containers like safe-deposit boxes, and it couldn’t hurt to soak an opal
in pure water from time to time. Opal jewelry should be cleaned with
mild soapy water and a soft brush or cloth.