Vesuvianite, also known as idocrase, is a green, brown, yellow, or blue
silicate mineral. Vesuvianite occurs as
tetragonal crystal
A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macros ...
s in
skarn deposits and
limestone
Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...
s that have been subjected to contact
metamorphism
Metamorphism is the transformation of existing rock (the protolith) to rock with a different mineral composition or texture. Metamorphism takes place at temperatures in excess of , and often also at elevated pressure or in the presence of chem ...
.
[ It was first discovered within included blocks or adjacent to ]lava
Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or un ...
s on Mount Vesuvius, hence its name. Attractive-looking crystals are sometimes cut as gemstones. Localities which have yielded fine crystallized specimens include Mount Vesuvius and the Ala Valley near Turin, Piedmont
it, Piemontese
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.
The specific gravity
Relative density, or specific gravity, is the ratio of the density (mass of a unit volume) of a substance to the density of a given reference material. Specific gravity for liquids is nearly always measured with respect to water (molecule), wa ...
is 3.4 and the Mohs hardness
The Mohs scale of mineral hardness () is a qualitative ordinal scale, from 1 to 10, characterizing scratch resistance of various minerals through the ability of harder material to scratch softer material.
The scale was introduced in 1812 by th ...
is . The name "vesuvianite" was given by Abraham Gottlob Werner
Abraham Gottlob Werner (; 25 September 174930 June 1817) was a German geologist who set out an early theory about the stratification of the Earth's crust and propounded a history of the Earth that came to be known as Neptunism. While most tenet ...
in 1795, because fine crystals of the mineral are found at Vesuvius; these are brown in color and occur in the ejected limestone blocks of Monte Somma
Mount Somma ( it, Monte Somma) is a mountain located in the Province of Naples, in the Campania region of southern Italy. Mount Somma is an integral part of the Somma–Vesuvius volcanic complex. It is high.
Geography
Mount Somma is the rem ...
. Several other names were applied to this species, one of which, "idocrase" by René Just Haüy in 1796, is now in common use.
A sky bluish variety known as ''cyprine'' has been reported from Franklin, New Jersey and other locations; the blue is due to impurities of copper in a complex calcium aluminum sorosilicate. ''Californite'' is a name sometimes used for jade
Jade is a mineral used as jewellery or for ornaments. It is typically green, although may be yellow or white. Jade can refer to either of two different silicate minerals: nephrite (a silicate of calcium and magnesium in the amphibole group of ...
-like vesuvianite, also known as ''California jade'', ''American jade'' or ''Vesuvianite jade''. ''Xanthite'' is a manganese
Manganese is a chemical element with the symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese is a transition metal with a multifaceted array of industrial alloy use ...
rich variety. Wiluite
Wiluite is a dark green, brownish, or black blocky silicate mineral with the chemical formula . It has a Mohs hardness of 6 and a specific gravity of 3.36. It has a vitreous lustre, poor cleavage and an irregular brittle fracture. It crystallizes ...
is an optically positive variety from Wilui, Siberia
Siberia ( ; rus, Сибирь, r=Sibir', p=sʲɪˈbʲirʲ, a=Ru-Сибирь.ogg) is an extensive geographical region, constituting all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has been a part of ...
. Idocrase is an older synonym sometimes used for gemstone
A gemstone (also called a fine gem, jewel, precious stone, or semiprecious stone) is a piece of mineral crystal which, in cut and polished form, is used to make jewelry or other adornments. However, certain rocks (such as lapis lazuli, opal, ...
-quality vesuvianite.
References
Additional sources
*
Webmineral data
Vesuvianite at Franklin-Sterling
{{Authority control
Calcium minerals
Magnesium minerals
Aluminium minerals
Mount Vesuvius
Gemstones
Geology of Italy
Sorosilicates
Tetragonal minerals
Minerals in space group 126