Zircon

The name "zircon" is believed to have derived from the Arabic words, "zar",
meaning gold, and "gun", meaning color. For many centuries, the brilliance
of zircon has captured the hearts of those who gazed upon this magnificent
gemstone. Zircon's popularity began to grow in the sixth century when
Italian artisans featured the stone in jewelry designs. During the Middle
Ages, zircon was believed to contain curative powers, protecting the wearer
from diseases and banishing insomnia.

Zircon is a minor gem, but a valuable source of zirconium metal and a major
mineral for today's geologists. Zircon always occurs in crystals. Although
the middle may be stretched into long prisms. Most often brown, zircon also
can be blue, green, red, or colorless. Gem zircons are usually turned blue
by heating brown or clear stones.

Zircon has a very high melting point, is fairly hard (Mohs hardness
6.5-7.5), and is resistant to weathering. As a result, zircon grains can
remain unchanged after being eroded from their mother granites, incorporated
into sedimentary rocks, and even metamorphosed. That makes zircons valuable
as mineral fossils.

Varieties - High, medium and low property.

Sources - Sri Lanka, Burma, Cambodia, Thailand.

History - The terms hyacinth or jacinth were often applied to the
reddish-brown zircon. During the Middle Ages, hyacinth was claimed to have
the power of inducing sleep, of promoting riches, honour and wisdom and of
driving away plagues and evil spirits. The pale yellow to colourless stones
from Ceylon (Sri Lanka) were called jargoons.

Zircon has long had a supporting role to more well-known gemstones, often
stepping in as an understudy when they were unavailable. In the middle ages,
zircon was said to aid sleep, bring prosperity, and promote honor and wisdom
in its owner. The name probably comes from the Persian word zargun which
means "gold-colored," although zircon comes in a wide range of different
colors.
Zircon occurs in a wide range of colors but for many years, the most popular
was the colorless variety which looks more like diamond than any other
natural stone due to its brilliance and dispersion.

Today the most popular color is blue zircon. Most blue zircon, which is
considered an alternate birthstone for December, is a pastel blue, but some
exceptional gems have a bright blue color. Zircon is also available in
green, dark red, yellow, brown, and orange.

Zircon is mined in Cambodia, Sri Lanka, Thailand, Myanmar, Australia, and
other countries.

Zircon is one of the heaviest gemstones, which means that it will look
smaller than other varieties of the same weight. Zircon jewelry should be
stored carefully because although zircon is relatively hard, it can abrade
and facets can chip. Dealers often wrap zircons in individual twists of
paper so that they will not knock against each other in a parcel.

The pervasive occurrence of zircon has become more important since the
discovery of radiometric dating. Zircons contain amounts of uranium and
thorium (from 10 ppm up to 1 wt%) and can be dated using modern analytical
techniques. Since zircons have the capability to survive geologic processes
like erosion, transport, even high-grade metamorphism, they are used as
protolith indicators. The oldest minerals found so far are zircons from the
Narryer Gneiss Terrane, Yilgarn Craton, Western Australia, with an age of
4.404 billion years. This age is interpreted to be the age of
crystallization. These zircons are not only the oldest minerals on earth,
they also show another interesting feature. Their oxygen isotopic
composition has been interpreted to indicate that more than 4.4 billion
years ago there was already water on the surface of the Earth. This is a
spectacular interpretation that has been published in top scientific
journals but is currently the subject of debate. It may be that the oxygen
isotopes, and other compositional features (the rare earth elements), record
more recent hydrothermal alteration of the zircons rather than the
composition of the magma at the time of their original crystallization.

The wide variety of colors of zircon, its rarity, and its relatively low
cost make it a popular collector's stone. Collectors enjoy the search for
all possible colors and variations.