Quartz: Common Chameleon
If you gaze deep into a crystal ball, you will see a versatile gemstone, one of
the most popular gems on earth. Beautiful quartz, the 'rock crystal' used in
ancient times to make crystal balls and bowls, is today more often seen set in
gold jewelry. Despite the popularity of quartz gems like amethyst, citrine,
ametrine, rose quartz, onyx, agates, chrysoprase, rutilated quartz and other
varieties, many people in the jewelry industry take quartz for granted because
of its affordable price.
Throughout history, quartz has been the common chameleon of gemstones, standing
in for more expensive gemstones ranging from diamond to jade. But the incredible
variety of quartz is now beginning to be appreciated in its own right.
Purple to violet amethyst and yellow to orange citrine are jewelry staples that
continue to increase in popularity. Ametrine combines the appeal of both
amethyst and citrine, purple and yellow in one gemstone. Different colors and
types of chalcedony, from agate to chrysoprase, have grown in popularity with
the growing appreciation for carved gemstones and artistic cutting and carving.
And unusual specialties like drusy quartz, with its surface covered by tiny
sparking crystals, and rutilated quartz, which has a landscape of shining gold
needles inside it, are adding variety and nature's artistry to unusual
one-of-a-kind jewelry.
Rose quartz
The pale pink color of quartz, which can range from transparent to translucent,
is known as rose quartz. The color is a very
pale and delicate
powder pink. Transparent rose quartz is very rare, and usually so pale that it
does not show very much color at all except in large sizes. Translucent rose
quartz is much more readily available, being used for beads, cabochons,
carvings, and architectural purposes.
Smoky
quartz
Smoky quartz is a brown transparent quartz that is sometimes used for unusual
faceted cuts. The commercial market is limited, because there is a rather
limited demand for brown gemstones. This variety was sometimes known as smoky
topaz in the past, though the term is incorrect and misleading.
Tiger's eye
Tiger's eye quartz contains brown iron which produces its golden yellow color.
Cabochon cut stones of this variety show the chatoyancy (small ray of light on
the surface)
that resembles the feline eye of a tiger. The most important deposit is in
Rock crystal
The transparent, colorless variety of quartz is still known as rock crystal.
Long ago, people believed that rock crystal was a compact form of ice: in fact 'crystallos'
means 'ice'. The best rock crystal has the clarity and shimmer of water.
Although colorless quartz is relatively common, large flawless specimens are
not, which is why crystal balls these days are made of glass, not quartz. Rock
crystal has often been used in jewelry, particularly carved pieces. Many
stunning art deco jewelry designs featured the black and white quartz
combination of rock crystal and onyx. Colorless quartz crystals have also become
popular in jewelry due to the popularity of legends about their powers. Many
people believe that wearing quartz crystals benefits their health and spiritual
well-being.
Rutilated
quartz and tourmilated quartz
While most varieties of transparent quartz are valued most when they show no
inclusions, some are valued chiefly because of them! The
most popular of these is known as rutilated quartz. Rutilated quartz is
transparent rock crystal with golden needles of rutile arrayed in patterns
inside it. Each pattern is different and some are breathtakingly beautiful. The
inclusions are sometimes called Venus hair. Less well known is a variety called
tourmilated quartz which, instead of golden rutile, has black or dark green
tourmaline crystals.
Chalcedonies
Quartz that is formed not of one single crystal but a number of finely grained
microcrystals is known as chalcedony. The variety of chalcedonies is even
greater than that of transparent quartz, including cryptocrystalline quartz with
patterns as well as a wide range of solid colors. Agates are banded. Bloodstone
has red spots on a green background. Moss agate has a plant-like pattern. Jasper
sometimes looks like a landscape painting. Another staple of the jewelry
industry is black onyx, chalcedony quartz which owes its even black color to an
ancient dyeing process that is still used today. Carnelian, another chalcedony
valued in the ancient world, has a vivid brownish orange color and clear
translucency that makes it popular for signet rings and seals. Chrysoprase, a
bright, apple green, translucent chalcedony, is the most valued. It was a
particular favorite of Frederick
The
Great of Prussia. It can be seen today decorating many buildings in beautiful