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The Mineral variscite

Sliced Variscite Nodule

Variscite is an important phosphate mineral that is best-known in different shades of green. A highly desired form of this mineral are the exceptional nodules from Utah which are cut and polished as slabs or halves of nodules. These formations are usually associated with other phosphates and have interesting veins and color habits.

Variscite may alter into other phosphate minerals, especially in its nodular form. It is often only partially altered, such as in yellowish to white layers or veins within a nodule that have been transformed to Crandallite.

Variscite is the end member of a series with Strengite, with Variscite being the aluminum-dominant member and Strengite being the iron-dominant member. Variscite sometimes contains some iron in its structure. The color caused by iron will dominate, and will cause some Variscite to have a violet or reddish color even if there is less iron than aluminum present.

Variscite is named after the German district of Variscia, where this mineral was first found. Variscia is the old historical name of the current region of Vogtland.

For additional information, see the gemstone section on Variscite.

Chemical Formula

AlPO4 · 2(H2O)

Color

Light green to emerald-green, apple-green, and bluish-green. Rarely purple, orange, pink, red, brown, or yellow. Often splotchy or multicolored with different shades of green.

Crystal System

Orthorhombic

Properties

Streak
White
Hardness
3.5 - 4.5
Transparency
Translucent to opaque. Rarely transparent.
Specific Gravity
2.5 - 2.6
Luster
Vitreous, waxy
Cleavage
1,1;2,1
Fracture
Splintery, uneven
Tenacity
Brittle

Crystal Habits

Most often grainy, encrusting, as rounded balls, nodular, botryoidal, reniform, in veins, and massive. Visible crystals are very rare, and are usually associated in rounded aggregates of hemispherical balls.

Additional Information

Composition
Aluminum phosphate, often with some iron
In Group
Phosphates; True Phosphates
Striking Features
Color, formation habits, and mode of occurrence.
Environment
As a secondary mineral in hydrothermal replacement deposits and brecciated sandstones.
Rock Type
Sedimentary, Metamorphic

Other Names

Utahlite Synonym of Variscite. May also refer to the nodular or thick variety that originates from Utah.

Varieties

 -   Variscite intergrown with Quartz or Chalcedony. The term is an abbreviated form of American Matrix.
 -   Variscite intergrown with Quartz or Chalcedony.

Uses

The polished, emerald-green nodules of Variscite that originate in Utah are highly valued among collectors. Variscite is also used a minor green, often splotchy, opaque gemstone.

Noteworthy Localities

The finest localities for this mineral are in Utah. The most outstanding and best-known is Clay Canyon, near Fairfield, Utah County, where this mineral is found in veined nodules with other phosphates. Fairfield Variscites are usually sliced and polished for collectors, and their color ranges from light bluish-green to deep emerald-green. Another important Utah deposit is the Utahlite Claim, in the Lucin District, Box Elder County, where it occurs in large thick masses and nodules and is mined for gemstone use.

Arkansas contains two notable deposits of Variscite, where it occurs as microcrystal crusts in the phosphate deposits associated with Wavellite in Dug Hill near Avant, Garland County; and in Mauldin Mountain, Montgomery County.

Rounded, reniform Variscite globs come from Wiśniówka Wielka, Świętokrzyskie, Poland; and green crusts from Palazuelo de las Cuevas, Zamora Province, Spain. Outstanding ball-like hemispherical crystal clusters were found in Itumbiara, Goias, Brazil; and bright pink and red, iron-rich Variscite came from the Boa Vista Mine, Galilea, Minas Gerais, Brazil; as well as the Iron Monarch Mine, Iron Knob, South Australia.

Common Mineral Associations

Limonite, Quartz, Chalcedony, Wavellite, Apatite, Crandallite, Wardite

Distingushing Similar Minerals

Turquoise may be very similar and very difficult to distinguish from Variscite, though Variscite is usually greener whereas Turquoise is bluer. Chrysocolla may also be similar though it is lower in hardness and usually has a more vitreous luster. Chrysoprase is much harder.


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