Charoite pronounced CHAR-oh-ite, is a rare mineral, first described in 1978 and named for the Chara River

Chara River

The Chara River is an long tributary of the Olyokma in Eastern Siberia, Russia.-Course:The Chara begains as an outflow of the Bolshoye Leprindo lake in the Kodar Mountains, in the northern Zabaykalsky Krai. It flows through the Chara Basin between the Kodar and Kalar Mountains, passing the Chara...

. It has been reported only from the Sakha Republic, Yakutia, Siberia

Siberia

Siberia is an extensive region constituting almost all of Northern Asia. Comprising the central and eastern portion of the Russian Federation, it was part of the Soviet Union from its beginning, as its predecessor states, the Tsardom of Russia and the Russian Empire, conquered it during the 16th...

, Russia

Russia

Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...

. It is found where a syenite

Syenite

Syenite is a coarse-grained intrusive igneous rock of the same general composition as granite but with the quartz either absent or present in relatively small amounts Syenite is a coarse-grained intrusive igneous rock of the same general composition as granite but with the quartz either absent or...

, the Murunskii Massif

Massif

In geology, a massif is a section of a planet's crust that is demarcated by faults or flexures. In the movement of the crust, a massif tends to retain its internal structure while being displaced as a whole...

, has intruded into and altered limestone

Limestone

Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....

 deposits producing a potassium feldspar metasomatite

Metasomatism

Metasomatism is the chemical alteration of a rock by hydrothermal and other fluids.Metasomatism can occur via the action of hydrothermal fluids from an igneous or metamorphic source. In the igneous environment, metasomatism creates skarns, greisen, and may affect hornfels in the contact...

.

Charoite is translucent lavender to purple in color with a pearly lustre. However, it is a discrete mineral

Mineral

A mineral is a naturally occurring solid chemical substance formed through biogeochemical processes, having characteristic chemical composition, highly ordered atomic structure, and specific physical properties. By comparison, a rock is an aggregate of minerals and/or mineraloids and does not...

 rather than a rock. Charoite is strictly massive in nature, and fractures are conchoidal. It has an unusual swirling, fibrous appearance, sometimes chatoyant, and that, along with its intense color, can lead many to believe at first that it is synthetic or enhanced artificially.

Though reportedly discovered in the 1940s, it was not known to the outside world until its description in 1978. It is said to be opaque and unattractive when found in the field; a fact that may have contributed to its late recognition. Charoite is used as an ornamental stone and sometimes a gemstone

Gemstone

A gemstone or gem is a piece of mineral, which, in cut and polished form, is used to make jewelry or other adornments...

, generally as cabochon

Cabochon

A cabochon , from the Middle French caboche , is a gemstone which has been shaped and polished as opposed to faceted. The resulting form is usually a convex top with a flat bottom. Cutting en cabochon is usually applied to opaque gems, while faceting is usually applied to transparent stones...

s set into pendants.

Charoite occurs in association with tinaksite

Tinaksite

Tinaksite is a mineral found in northern Russia. Tinaksite can be grayish-white, yellowish, orange, or brown, and it is often found in charoite. Its name is derived from its composition: titanium , sodium potassium and silicon . International Mineralogical Association first recognized tinaksite...

 and canasite.