Mariposite is a
mineral
In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. (2 ...
which is a
chromium-rich variety of
mica, which imparts an attractive green color to the generally white
dolomitic marble
Marble is a metamorphic rock composed of recrystallized carbonate minerals, most commonly calcite or dolomite. Marble is typically not foliated (layered), although there are exceptions. In geology, the term ''marble'' refers to metamorphose ...
in which it is commonly found. It was named for
Mariposa, California
Mariposa (; Spanish for "Butterfly") is an unincorporated community and census-designated place (CDP) in and the county seat of Mariposa County, California, United States. The population was 1,526 at the 2020 census. The community is named afte ...
, United States, though it can be found in several other places in the
Sierra Nevada. It is also found in
Marblemount, Washington
Marblemount is a Census-designated places, census-designated place in Skagit County, Washington, United States. The population was 203 at the 2010 United States Census, 2010 census. It is included in the Mount Vernon, Washington, Mount Vernon&ndash ...
, in the
North Cascades
The North Cascades are a section of the Cascade Range of western North America. They span the border between the Canadian province of British Columbia and the U.S. state of Washington and are officially named in the U.S. and Canada as the Casca ...
, as well as in a few locations in
Newfoundland, Canada, where it is called virginite, and in
Europe
Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located entirel ...
.
It is not an officially classified mineral, but is a chromium-rich
phengite, which is a high silica variety of
muscovite
Muscovite (also known as common mica, isinglass, or potash mica) is a hydrated phyllosilicate mineral of aluminium and potassium with formula K Al2(Al Si3 O10)( F,O H)2, or ( KF)2( Al2O3)3( SiO2)6( H2O). It has a highly perfect basal cleavag ...
. It is the chromium that gives it its distinctive green color.
The term "mariposite" also refers to the
stone
In geology, rock (or stone) is any naturally occurring solid mass or aggregate of minerals or mineraloid matter. It is categorized by the minerals included, its Chemical compound, chemical composition, and the way in which it is formed. Rocks ...
in which the green mica is found. This stone is
metamorphic rock
Metamorphic rocks arise from the transformation of existing rock to new types of rock in a process called metamorphism. The original rock ( protolith) is subjected to temperatures greater than and, often, elevated pressure of or more, caus ...
, containing varying amounts of
dolomite and
quartz
Quartz is a hard, crystalline mineral composed of silica ( silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical ...
. Larger proportions of quartz give it a more attractive, translucent appearance. It is used as a decorative construction material, in walls, monuments, and bridges. It is also made into
jewelry
Jewellery ( UK) or jewelry ( U.S.) consists of decorative items worn for personal adornment, such as brooches, rings, necklaces, earrings, pendants, bracelets, and cufflinks. Jewellery may be attached to the body or the clothes. From a w ...
.
Chemical composition
The chemical formula of mariposite is .
References
{{reflist
External links
Mariposite from the Alameda Mine by Mindat
Potassium minerals
Aluminium minerals
Chromium minerals
Mica group
Mariposa County, California