Clear
Quartz
or
Rock Crystal
VARIETY INFORMATION:
- VARIETY OF: Quartz , SiO 2
, Silicon Dioxide .
- USES: Ornamental stone and gemstone.
- COLOR: Colorless.
- INDEX OF REFRACTION: 1.544-1.553
- BIREFRINGENCE: 0.009
- HARDNESS: 7
- CLEAVAGE: none
- CRYSTAL SYSTEM: trigonal
Rock crystal is the name given to all clear colorless quartz.
It is widely used as a popular ornamental stone and is also used as a gemstone.
Although it is one of the lest expensive gemstones, cut rock crystal has been
used as imitation diamonds. Rock crystal lacks the fire, color (of course) and
the rarity to be ranked as a fine precious gemstone. None-the-less, rock crystal
is in wide use as a gemstone due to its beauty, affordability, availability and
ease of cutting.
The most use for rock crystal is in ornamental carvings. The
most well known ornamental carving for rock crystal is the crystal ball of
fortune telling fame. While rock crystal is common it is hard to find large
crystals of quartz with the clarity and size required for crystal balls that
most of us associate with fortune tellers. Rock crystal is used for many
ornamental carvings from spheres (crystal balls) to pyramids to obelisks to
figurines to eggs to bowls to wands. There are many fine chandeliers that are
outfitted with rock crystal ornaments.
Many people prefer uncut clusters of rock crystal. These
natural treasures look like crystal cities of fantasy stories. The long slender
clear prisms of quartz projecting upward from a common base are true mineralogic
wonders that can be admired by all. They cost of good clusters of rock crystal
is still affordable and comes from sources around the world. The best rock
crystal sources are in the famous Hot Springs area of Arkansas, USA; Cumberland,
England; St. Gotthard, Switzerland; Brazil and Madagascar. Large individual
crystals of quartz have been found in Brazil, the largest weighs over 44 tons.
Rock crystal often has inclusions of other minerals and these
inclusions sometimes produce popular varieties of ornamental stone. Golden
rutile inclusions produce a unique stone aptly named rutilated quartz
that has a very hair-like look. Another apply named stone is called tourmalinated
quartz and contains intricately crossing needles of black schorl tourmaline
trapped in the clear crystal.
Phantoms are a result of inclusions which occur when other
minerals such as chlorite, hematite, or even milky quartz form as a crust on the
surface of the crystals during an hiatus in the crystal's growth. The crystal
then grows out and around the encrusting growth encasing it inside. But since
the thin encrustations formed over a crystal complete with crystal faces it
appears that there is a crystal inside the crystal. The encrustations are often
incomplete or diffuse and appear ghostly, hence the name phantom.
Serendipity
Ranch Gem Mine