Mineral Key
Green Stone – Luck Stone, Charlottesville Quarry
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Catoctin Greenstone, is a rock formation created from volcanic lava flows over
500 million years ago. The Catoctin originated as a type of lava called basalt,
which contains plagioclase and pyroxene minerals. During the mountain
building processes responsible for the Appalachians, epidote and chlorite
infused the formation with what it is known for today, its popular green color.
If you wet the dust sample lightly with a spray bottle, the color will be more
evident.
Greenstone is used as an aggregate to help build roads, schools, and houses.
This particular deposit can also be found in Har-Tru Green Clay Tennis Courts.
Soap Stone – Alberene Soapstone Company
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Soapstone is the common name for Steatite, which is a magnesium silicate
composed of talc and magnesium, making this is a very soft stone with a high
density. Soapstone is a Metamorphic rock that was altered from its original
physical form by heat and pressure millions of years ago. This particular
deposit is highly foliated, or layered, with white quartz veins.
This rock has historically been mined for use in interior design and sculpture.
Heavy Mineral Sands – Illuka
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Deposits of mineral sands are formed along ancient coastlines where the
heavier minerals have been concentrated by wave and wind action. Most
mineral sand deposits are found in unconsolidated fossil shorelines several
hundred meters inland from the present coastline. The composition of mineral
sands deposits reflects the type of rocks from which the sands containing the
heavy minerals are derived. For example, granitic and gneissic source rocks
principally provide ilmenite and zircon, while metamorphic rocks provide
ilmenite and rutile.
This material is approximately 60% ilmenite, 3% leucoxene, 15% zircon, 10%
staurolite, ~6% kyanite & silliminite, and can be used in refractories, foundries
and casting applications.
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Vermiculite– Virginia Vermiculite LLC
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Vermiculite is a hydrous magnesium silicate containing varying amounts of iron
and aluminum. It is generally considered to be an alteration product of mica. In
fact, vermiculite concentrate resembles mica in appearance. Vermiculate has
the unique property of expanding or popping like popcorn when subjected to
heat. Vermiculate contains water in the crystal structure, and when heated to
1500°F the water vaporizes, and the layers of vermiculite spread out.
Expanding vermiculite simulates the opening out of an accordion. The
resemblance of expanded vermiculite to worms gives the material its name:
the Latin word vermiculus means little worm.
Vermiculite is used as loose insulation in block walls, as a growing medium in
greenhouses, and in its expanded form, vermiculite is used in the production of
fire-rated wallboard required in garages and commercial buildings.
Kyanite– Virginia Kyanite
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Kyanite is an aluminosilicate mineral, composed of aluminum, silicon and
oxygen. In its most pure form, Kyanite occurs as a blue crystal. Kaynite is found
in a quartzite host rock within the Chopawamsic Formation, which is a series of
Ordovician age metavolcanic and metasedimenaty rocks. The mineral has the
irreversible property of expanding when heated to a certain temperature.
Kyanite is used in a large number of products, including furnace bricks, kiln
furniture, brake shoe lining, pottery, electronic ceramics and sanitary ware.
Marble– Boxley, Lawyers Road Quarry
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Marble is metamorphic rock that formed when limestone was exposed to high
levels of heat and pressure. The formation of marble generally occurs near
convergent plate boundaries or contact metamorphism, when a neighboring
magma body alters the limestone deposit. Calcite is the largest component of
marble while Iron, Aluminum, and Sulfur can also be found in the rock.
Marble is crushed to be used in the construction of roads and buildings, or
mined as a dimension stone used in sculpting or architecture.
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Diabase– Vulcan Materials, Manassas Quarry
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This Traprock is a dense igneous rock, dark colored, greenish-black to bluish
black. It was formed as hot magma surfaced from within the earth through
fractures in other rocks already present near the surface. It is found in an area
stretching from Frederick, Maryland down to near Gordonsville, Va. This area
experience activity around 200 million years ago which caused the Diabase
magma to rise up through existing rock and spread out on the surface in
volcanic flows know as sills. The sills cooled into a hard rock composed mainly
of pyroxene, a dark mineral containing iron, and plagioclase. Other minerals
leading to the green-black color are epidote and hornblende.
Diabase is used mainly as a construction aggregate in the building of roads,
homes and businesses.
Granite– Martin Marietta, Anderson Creek Quarry
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This rock is a metavolcanic in nature and was formed in the early Paleozoic
time, about 500 million years ago. Occurring first as a volcanic flow of lava or
magma, the rock then experience high heat and pressures, causing the minerals
to become more distinct. The deposit has many joints and fractures
throughout, which indicates that the formation underwent intense folding. The
rock tends to be a green-gray and fine-grained in texture, but has visible red
feldspar and quartz.
Granite can be used as an aggregate in construction and can also be found in
many households and businesses as an architectural stone.
Limestone– Luck Stone/Carmeuse
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Limestone is a sedimentary rock which tends to form in shallow marine
environments. The rock is chemical or organic in nature, composing of lime
mud and crystalline calcite, and will tend to contain fossils of marine life.
Limestone is fairly soluble in water and week acid solutions, which explains a
tendency for caverns and caves to form in limestone deposits.
Limestone has many uses, including the steel, paper and pulp, mining, glass,
water and waste treatment, and construction industries.
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Sources
"Alberene Soapstone." Alberene Soapstone RSS. N.p., n.d. Web. 14 Oct. 2014.
"Block . Brick . Readymix Concrete . Aggregate . Roanoke & Lynchburg, VA . West Virginia .
Boxley." Block . Brick . Readymix Concrete . Aggregate . Roanoke & Lynchburg, VA . West
Virginia . Boxley. N.p., n.d. Web. 14 Oct. 2014.
"Common Minerals of Virginia." DMME. N.p., n.d. Web. 12 Oct. 2014.
"Common Rocks of Virginia." DMME. N.p., n.d. Web. 14 Oct. 2014.
"Iluka." Products End Applications. N.p., n.d. Web. 14 Oct. 2014.
King, Hobart M., Ph.D. "Marble." Metamorphic Rock. N.p., n.d. Web. 12 Oct. 2014.
"Kyanite Mining Corporation - Home." Kyanite Mining Corporation - Home. N.p., n.d. Web. 14 Oct.
2014.
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