Variscite is a hydrated
aluminium phosphate
Aluminium phosphate is a chemical compound. In nature it occurs as the mineral berlinite. Many synthetic forms of aluminium phosphate are known. They have framework structures similar to zeolites and some are used as catalysts, ion-exchangers or ...
mineral (). It is a relatively rare phosphate mineral. It is sometimes confused with
turquoise
Turquoise is an opaque, blue-to-green mineral that is a hydrated phosphate of copper and aluminium, with the chemical formula . It is rare and valuable in finer grades and has been prized as a gemstone and ornamental stone for thousands of yea ...
; however, variscite is usually greener in color. The green color results from the presence of small amounts of trivalent
chromium
Chromium is a chemical element with the symbol Cr and atomic number 24. It is the first element in group 6. It is a steely-grey, lustrous, hard, and brittle transition metal.
Chromium metal is valued for its high corrosion resistance and hardne ...
().
Geology
Variscite is a secondary mineral formed by direct deposition from phosphate-bearing water that has reacted with aluminium-rich rocks in a near-surface environment. It occurs as fine-grained masses in
nodules, cavity fillings, and crusts. Variscite often contains white veins of the calcium aluminium phosphate mineral
crandallite
Crandallite is a calcium aluminium basic phosphate mineral. It has ideal formula .
Crandallite was named after Milan L. Crandall, Jr, who worked for Knight Syndicate.
This mineral is found in laterite and in alteration products of phosphate rich ...
.
It was first described in 1837 and named for the locality of
Variscia
Vogtland (; cz, Fojtsko) is a region spanning the German states of Bavaria, Saxony and Thuringia and north-western Bohemia in the Czech Republic. It overlaps with and is largely contained within List of euroregions, Euregio Egrensis. The name a ...
, the historical name of the
Vogtland
Vogtland (; cz, Fojtsko) is a region spanning the German states of Bavaria, Saxony and Thuringia and north-western Bohemia in the Czech Republic. It overlaps with and is largely contained within Euregio Egrensis. The name alludes to the former ...
, in Germany. At one time, variscite was called ''Utahlite''. At times, materials which may be
turquoise
Turquoise is an opaque, blue-to-green mineral that is a hydrated phosphate of copper and aluminium, with the chemical formula . It is rare and valuable in finer grades and has been prized as a gemstone and ornamental stone for thousands of yea ...
or may be variscite have been marketed as "variquoise". Appreciation of the color ranges typically found in variscite have made it a popular gem in recent years.
[Minerals of Nevada - Nevada Bureau of Mines Special Pub. 31 University of Nevada Press, 2004 Pages 78-81]
Variscite from Nevada typically contains black spiderwebbing in the matrix and is often confused with green turquoise. Most of the Nevada variscite recovered in recent decades has come from mines located in
Lander County
Lander County is a county in the U.S. state of Nevada. As of the 2020 census, the population was 5,734. Its county seat is Battle Mountain.
History
Lander County was created in 1862 as the result of a mining boom on the Reese River along the ...
and Esmeralda County, specifically in the Candelaria Hills.
Notable localities are
Lucin,
Snowville, and
Fairfield in
Utah
Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to it ...
,
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...
. Most recently found in
Wyoming
Wyoming () is a U.S. state, state in the Mountain states, Mountain West subregion of the Western United States. It is bordered by Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the south ...
as well. It is also found in
Germany
Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...
,
Australia
Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...
,
Poland
Poland, officially the Republic of Poland, is a country in Central Europe. It is divided into 16 administrative provinces called voivodeships, covering an area of . Poland has a population of over 38 million and is the fifth-most populous ...
,
Spain
, image_flag = Bandera de España.svg
, image_coat = Escudo de España (mazonado).svg
, national_motto = ''Plus ultra'' (Latin)(English: "Further Beyond")
, national_anthem = (English: "Royal March")
, i ...
and
Brazil
Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...
.
Jewelry
Variscite is sometimes used as a semi-precious stone, and is popular for carvings and ornamental use due to its beautiful and intense green color, and is commonly used in
silversmithing
A silversmith is a metalworker who crafts objects from silver. The terms ''silversmith'' and ''goldsmith'' are not exactly synonyms as the techniques, training, history, and guilds are or were largely the same but the end product may vary great ...
in place of turquoise. Variscite is more rare and less common than
turquoise
Turquoise is an opaque, blue-to-green mineral that is a hydrated phosphate of copper and aluminium, with the chemical formula . It is rare and valuable in finer grades and has been prized as a gemstone and ornamental stone for thousands of yea ...
, but because it is not as commonly available as turquoise or as well known to the general public, raw variscite tends to be less expensive than turquoise.
Gallery
Variscite Smithsonian.jpg, Cut slab of variscite at the Smithsonian. Specimen is roughly 0.5 m wide.
00021 11 cm variscite.jpg, Variscite filling the cracks in siltstone. The sample is from Queensland, Australia. The width of the view is .
Varis mcguin damali.jpg, Polished variscite from Nevada.
Variscite-bolo.jpg, Variscite and silver bolo tie
A bolo tie (sometimes bola tie or shoestring necktie) is a type of necktie consisting of a piece of cord or braided leather with decorative metal tips (called aiguillettes) and secured with an ornamental clasp or slide.
Popularity
In the United ...
. This variscite specimen contains inclusions of white crandallite and is from Clay Canyon near Fairfield, Utah
Fairfield is a town in Utah County, Utah, United States. It is part of the Provo–Orem, Utah Metropolitan Statistical Area. It is located in the southwest corner of Cedar Valley about southwest of Salt Lake City and south of Cedar Fort ...
See also
* (same etymology, as named from the ancient locality of
Variscia
Vogtland (; cz, Fojtsko) is a region spanning the German states of Bavaria, Saxony and Thuringia and north-western Bohemia in the Czech Republic. It overlaps with and is largely contained within List of euroregions, Euregio Egrensis. The name a ...
in Germany)
*
List of minerals
This is a list of minerals for which there are articles on Wikipedia.
Minerals are distinguished by various chemical and physical properties. Differences in chemical composition and crystal structure distinguish the various ''species''. Within a m ...
References
Aluminium minerals
Phosphate minerals
Orthorhombic minerals
Minerals in space group 61
Luminescent minerals
Gemstones
Hydrates
{{Phosphate-mineral-stub