Rock crystal is generally refered to as quartz crystal.
It is the transparent and colorless macrocrystalline variety of the mineral Quartz (SiO2).
Links To Rock Crystal Quartz Information Topics On This Page:
To see photos of another mineral variety, select any link from our Mineral Inventory & Factsheet Index.
Rock crystal is a macrocrystalline variety of the mineral Quartz (SiO2). Quartz is the most abundant single mineral on earth. It makes up about 12% of the earth's crust, occurring in a wide variety of igneous, metamorphic and sedimentary rocks.
Quartz varieties are commonly separated into two groups based on the size of the individual grains or crystals; macrocrystalline quartz in which individual crystals are distinguishable with the naked eye, and cryptocrystalline quartz in which the individual crystals are too small to be easily distinguishable under the light microscope.
Some of the macrocrystalline quartz varieties are: Amethyst, Ametrine, Cat's-eye Quartz, Citrine, Phantom Quartz, Rock Crystal, Rose Quartz, Rutilated Quartz, Smoky Quartz and Strawberry Quartz.
Blue Aventurine Quartz and Green Aventurine Quartz are actually quartzites (a rock, not a mineral) composed essentially of interlocking macrocrystalline quartz grains with disseminated grains of other color imparting minerals.
The cryptocrystalline varieties of quartz may be separated into two types;
fibrous and microgranular. Chalcedony is the general term
applied to the fibrous cryptocrystalline varieties.
Agate is an example of a fibrous cryptocystalline
banded chalcedony variety of quartz. Carnelian, Chrysoprase and bloodstone
are other chalcedony varieties.
Chert is the general term applied to the granular cryptocrystalline varieties of quartz, of which flint and Jasper are examples.
Opal is a hydrous silica mineral composed of SiO2 with some water incorporated within its structure.
Return to the Index of Rock Crystal Quartz Information Topics
Rock crystal is transparent and colorless quartz. It commonly occurs in quartz veins where it crytallizes inside rock cavities known as vugs. It also is common in vugs or pockets in pegmatite dikes. Rock crystal often occurs as secondary quartz crystals on cryptocrystalline quartz in cavities and vugs, and in geodes.
Rock crystal often has minute cavity inclusions containing carbon dioxide or water. If there is a sufficient number of these minute fluid inclusions then the quartz becomes opaque and is called milky quartz. Most rock crystal forms on a matrix of milky quartz and crystals of rock crystal often grade into milky quartz towards their base. Rock crystal often has cavities containing both liguid and gas phases known as a two-phase inclusions. In rare cases, two-phase inclusions in quartz can be large enough to be visible to the unaided eye and may show actual movement of the gas phase within the liquid phase.
Rock crystal sometimes forms with an etched pattern of lines, depressions and raised terminations. If these etched terminations are accompanied by plainly visible internal cavities arranged in geometric patterns related to the quartz crystal structure, the form is referred to as skeletal or elestial quartz. The internal cavities of skeletal quartz often contain clay minerals of varied colors, sometimes accompanied by carbon dioxide or water. These cavities can have a layered or ribbed aspect and are sometimes so pronounced as to make the crystal almost hollow, giving rise to the term skeletal quartz. Occaisionally these cavities contain both liguid and gas phases together known as two-phase inclusions. In rare cases, these two-phase inclusions in skeletal quartz may show actual movement of the gas phase within the liquid phase (popularly known as elestial quartz crystal enhydros).
Natural radiation from radioactive impurities or adjacent radioactive rocks can cause rock crystal to assume a brown to gray color, known as smoky quartz. Minor iron impurities can cause rock crystal to be purple (amethyst) or yellowish-orange (citrine).
Many different minerals can form as inclusions within rock crystal. Some of the more important varieties of included quartz for gem use are rutilated quartz, tourmalinated quartz, cat's-eye quartz and strawberry quartz. This term strawberry quartz correctly refers to a very rare and beautiful (when polished) variety of natural quartz crystal with tiny red hair-like inclusions of hematite which glitter and shine as the material is turned under a light. Some other common mineral inclusions in rock crystal are chlorite, goethite and lepidocrosite.
Phantom quartz shapes are sometimes present in the interior of rock crystal, outlining an earlier stage of the rock crystal's crystallization. These phantoms are usually composed of other minerals such as chlorite or other varieties of quartz such as milky quartz or smoky quartz which form on most or all of the surfaces of a quartz crystal at a particular point in time during its growth, after which the quartz crystal resumes its crystallization enclosing the phantom crystal outline within itself.
Rock crystal is recognized by its crystal habit, transparency, hardness, glassy luster,
conchoidal fracture, occurance and general lack of cleavage.
Return to the Index of Rock Crystal Quartz Information Topics
Pliny wrote nearly 2000 years ago that rock crystal formed from ice by intense cold for long periods of time in dark clefts and caverns in the mountains. This general belief was popular in diverse cultures until the eighteenth century, when modern geology began to develope in Europe.
Rock crystal has been used as gemstones and other ornamental and religous objects for thousands of years. Polished rock crystal spheres or crystal balls were used as a means of divination or scrying in medieval times. In some ancient cultures, crystal skulls were believed to have special powers. For thousands of years, rock crystal and objects made from it have been used for divination, disease diagnosis and healing, and for awareness of current events in distant places by many different cultures.
Due to its piezoelectric properties, untwinned rock crystal is used as a radio oscillator to control transmission and reception on fixed frequencies. This same property is utilized in watches and clocks where a tiny quartz plate is used to control precisely the radio frequency of the electronic circuitry, thus telling the exact time. Rock crystal is also used as a chemical raw ingredient in the manufacture of numerous industrial materials.
Rock crystal is generally refered to as quartz crystal. The name quartz comes from the Saxon word querklufterz which meant cross vein ore. Crystal is from the Greek word krystallos which meant ice, due to the early Greek's belief that rock crystal formed from ice.
All of the astrological signs apply to rock crystal.
Rock crystal is the symbolic gemstone for the 15th wedding anniversary.
Rock crystal is considered to be the most usefull and versatile crystal for metaphysical purposes, usable in both its rough form and in a variety of sculpted items such as quartz spheres (crystal balls), quartz crystal gemstones, polished quartz crystals, obelisks, quartz pyramids, crystal skulls, massage tools, etc...
Rock crystal is said to stimulate mental clarity, emotional stability and to facilitate and focus meditative states. It is also said to stimulate positive thoughts and feelings, and to amplify psychic abilities. Rock crystal is said to help remove toxins from the body and to help treat disorders of the digestive system, kidneys and bladder. Rock Crystal also is said to be helpfull in treating a number of other ailments including pituitary gland disorders and skin, circulatory system and respiratory system disorders. Rock crystal is also said to help considerably in providing relief from pain, and to help in recovering from radiation exposure, and wearing quartz jewelry is said to significantly strengthen the immune system.
For more in-depth metaphysical information, see our Metaphysical Books section.
See our natural Crystal Balls and our genuine Quartz Jewelry.
Quartz (SiO2) is the most abundant single mineral on earth. It makes up about 12% of the earth's crust, occurring in a wide variety of igneous, metamorphic and sedimentary rocks.
There are many varieties of quartz. Quartz varieties are commonly separated into two groups based on the size of the individual grains or crystals; macrocrystalline quartz in which individual quartz crystals are distinguishable with the naked eye, and cryptocrystalline quartz in which the individual quartz crystals are too small to be easily distinguishable under the light microscope.
|Smoky Quartz||Strawberry Quartz|
We have been mining professionally for quartz crystals and other gems & minerals for more than 30 years, and we have a very large variety of natural quartz crystal products available.
We specialize in collector quality rock crystal quartz, crystal balls and polished quartz points. We also have some very large quartz crystals, large quartz crystal clusters, and large quartz crystal decorator specimens in stock, some weighing over 1500 pounds!
Just let us know if you like to be informed by email when we add more natural quartz crystal clusters & quartz crystals on our website.
Go Up To The Top of This Page