Kassite
Encyclopedia
Kassite is a rare mineral with formula CaTi2O4(OH)2. It crystallizes in the orthorhombic crystal system
and forms radiating rosettes and pseudo-hexagonal tabular crystals which are commonly twinned
. Crystals are brownish pink to pale yellow and are translucent with an adamantine luster. Cleavage is distinct and the crystals are very brittle.
It was first described in 1965 from the Afrikanda pyroxenite
massif
, Kola Peninsula
, Russia
and was named for Nikolai Grigorievich Kassin (1885–1949), Russian geologist. It occurs as miarolytic cavity fillings of alkalic pegmatite
s in the Kola occurrence and in nepheline syenite
in the Magnet Cove igneous complex
of Arkansas
, USA. Its mineral association includes cafetite
, perovskite
, titanite
, rutile
and ilmenite
. It is polymorphous with cafetite.
Crystal system
In crystallography, the terms crystal system, crystal family, and lattice system each refer to one of several classes of space groups, lattices, point groups, or crystals...
and forms radiating rosettes and pseudo-hexagonal tabular crystals which are commonly twinned
Crystal twinning
Crystal twinning occurs when two separate crystals share some of the same crystal lattice points in a symmetrical manner. The result is an intergrowth of two separate crystals in a variety of specific configurations. A twin boundary or composition surface separates the two crystals....
. Crystals are brownish pink to pale yellow and are translucent with an adamantine luster. Cleavage is distinct and the crystals are very brittle.
It was first described in 1965 from the Afrikanda pyroxenite
Pyroxenite
Pyroxenite is an ultramafic igneous rock consisting essentially of minerals of the pyroxene group, such as augite and diopside, hypersthene, bronzite or enstatite. They are classified into clinopyroxenites, orthopyroxenites, and the websterites which contain both pyroxenes...
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...
, Kola Peninsula
Kola Peninsula
The Kola Peninsula is a peninsula in the far northwest of Russia. Constituting the bulk of the territory of Murmansk Oblast, it lies almost completely to the north of the Arctic Circle and is washed by the Barents Sea in the north and the White Sea in the east and southeast...
, 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...
and was named for Nikolai Grigorievich Kassin (1885–1949), Russian geologist. It occurs as miarolytic cavity fillings of alkalic pegmatite
Pegmatite
A pegmatite is a very crystalline, intrusive igneous rock composed of interlocking crystals usually larger than 2.5 cm in size; such rocks are referred to as pegmatitic....
s in the Kola occurrence and in nepheline syenite
Nepheline syenite
Nephelene syenite is a holocrystalline plutonic rock that consists largely of nepheline and alkali feldspar. The rocks are mostly pale colored, grey or pink, and in general appearance they are not unlike granites, but dark green varieties are also known...
in the Magnet Cove igneous complex
Magnet Cove igneous complex
The Magnet Cove igneous complex is a small alkalic ring complex lying to the west of the town of Magnet Cove in Hot Spring County, Arkansas. It and the adjacent town are so named due to the existence of magnetite and the terrain being a cove, a basin-shaped valley.The complex is of Mesozoic age,...
of Arkansas
Arkansas
Arkansas is a state located in the southern region of the United States. Its name is an Algonquian name of the Quapaw Indians. Arkansas shares borders with six states , and its eastern border is largely defined by the Mississippi River...
, USA. Its mineral association includes cafetite
Cafetite
Cafetite is a rare titanium oxide mineral with formula 2Ti4O12·4).It was first described in 1959 for an occurrence in the Afrikanda Massif, Afrikanda, Kola Peninsula, Murmanskaja Oblast', Northern Region, Russia...
, perovskite
Perovskite
A perovskite structure is any material with the same type of crystal structure as calcium titanium oxide , known as the perovskite structure, or XIIA2+VIB4+X2−3 with the oxygen in the face centers. Perovskites take their name from this compound, which was first discovered in the Ural mountains of...
, titanite
Titanite
Titanite, or sphene , is a calcium titanium nesosilicate mineral, CaTiSiO5. Trace impurities of iron and aluminium are typically present...
, rutile
Rutile
Rutile is a mineral composed primarily of titanium dioxide, TiO2.Rutile is the most common natural form of TiO2. Two rarer polymorphs of TiO2 are known:...
and ilmenite
Ilmenite
Ilmenite is a weakly magnetic titanium-iron oxide mineral which is iron-black or steel-gray. It is a crystalline iron titanium oxide . It crystallizes in the trigonal system, and it has the same crystal structure as corundum and hematite....
. It is polymorphous with cafetite.