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Green Aventurine Quartz Information
Aventurine Information
Green aventurine is a quartzite, which is composed of macrocrystalline quartz grains with disseminated fuchsite mica as the color imparting mineral.
There are many named quartzite varieties, usually based on the color.
See also our other Varieties of Quartz
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GREEN AVENTURINE QUARTZ PHYSICAL PROPERTIES
- Green Aventurine Quartz chemical composition: SiO2
colored green by fuchsite mica: K(Al,Cr)2AlSi3O10(OH)2 - Class: tectosilicate
- Crystal system: Hexagonal-R; 32 (trigonal-trapezohedral)
- Crystal habit: massive aggregate of interlocking quartz grains
- Green Aventurine Quartz Specific gravity: 2.64 to 2.69
- Index of refraction: 1.55
- Birefringence: weak, maximum of 0.009
- Green Aventurine Quartz Hardness: 7
- Color: green
- Green Aventurine Quartz Luster: dull vitreous
- Green Aventurine Quartz Transparency: translucent to opaque
- Green Aventurine Quartz Cleavage: none
- Green Aventurine Quartz Fracture: conchoidal
- Streak: white
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QUARTZ (Green Aventurine) BACKGROUND INFORMATION
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.
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 and Smoky Quartz.
Green Aventurine Quartz and Blue 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.
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GREEN AVENTURINE QUARTZ OCCURRENCE AND DIAGNOSTIC FEATURES
Coarsely crystalline quartz is common in many rocks. Because of crystalline quartz's mechanical and chemical stability, it endures as detrital grains when quartz bearing rocks break down and these grains can accumulate as sand and pebbles in sedimentary deposits. Some sedimentary deposits are composed almost entirely of quartz grains which can become cemented together with time leading to the formation of sandstones. When a quartz-rich sedimentary deposit or a sandstone undergoes high grade metamorphism (metamorphism is the alteration of a rock due to changes in heat, pressure or chemical environment), the original material alters to a compact rock composed of interlocking quartz grains known as quartzite.
Other minerals may form within the quartzite during high grade metamorphism, depending on what impurities were present in the original sandstone or quartz-rich sedimentary deposit. Impurities present in the original material commonly alter to mica during high grade metamorphism. If chromium is present, then the green colored muscovite mica variety fuchsite can occur disseminated throughout the quartzite in parallel orientation giving it a green color and a spangled effect. This material is known as green aventurine quartz which is a popular lapidary material for making natural color green aventurine jewelry.
Green aventurine quartz is characterized by its occurance, hardness, conchoidal fracture, specific gravity, refractive index and luster. Quartzite is distinguished from sandstone by its fracture, which passes through the grains in quartzite and around the individual grains in sandstone.
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GREEN AVENTURINE QUARTZ HISTORICAL INFORMATION AND USES
The gem varieties of quartz have been used as gemstones and other ornamental objects for thousands of years. Aventurine rough has been worked by man into ornamental objects for thousands of years. Green aventurine quartz is a popular lapidary material today, showing an atractive natural green color when polished or when wet. In the past, green aventurine quartz has been miscalled Indian jade although the specific gravity and refractive index can readily identify aventurine quartz from jade.
Some of the earliest primitive stone tools (axes) fashioned by man's ancestors 2.5 million years ago in the Omo valley in Ethiopia, were made of quartz varieties such as quartzite. These materials were used because of their hardness and their isotropic brittleness which made it possible to shape the tools with relative ease.
Quartzite is also used as a building material.
The name quartz comes from a Saxon word meaning cross vein ore.The astrological sign of green aventurine quartz is aries.
Green aventurine quartz is an alternate birthstone for the month of August.
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GREEN AVENTURINE QUARTZ METAPHYSICAL PROPERTIES
Green aventurine quartz is said to relieve anxiety and calm one's emotions, to bring opportunity, to give good luck in gambling, and to enhance one's creativity and leadership qualities.
Fuchsite is said to enhance the body's ability to heal itself, and to increase the effectiveness of other minerals that are being used in healing.
Green aventurine quartz is also said to have been used successfully in psychotherapy, treating disorders of the lungs and heart, and to help increase muscle flexibility.
For more in-depth metaphysical information, see our Metaphysical Books section.
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See all of our natural varieties of quartz:
Varieties of QUARTZ
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Last Updated: February 15, 2021
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