Kochite is a rare silicate mineral with chemical formula of (Na,Ca)₃Ca₂(Mn,Ca)ZrTi[(F,O)₄(Si₂O₇)₂] or double that. Kochite is a member of the rosenbuschite group.

Crystallography

Kochite is triclinic with angles intersecting at approximately α 90.192°, β 100.192°, γ 111.551°. This mineral belongs to the space group P and is centrosymmetric, i.e. contains a center of symmetry.

Kochite is an anisotropic mineral. The light entering the mineral is split into two rays that vibrate at 90° to each other. Kochite is biaxial, meaning it has two optic axes (lines of symmetry). In plane polarized light, this mineral is colorless to light brown and is pleochroic. As the stage of the microscope is turned from X to Z the color changes from colorless to a pale brownish-yellow. Kochite is also a birefringent mineral, showing bright colors under crossed polarization. The birefringence of Kochite is .0340.

Discovery and occurrence

Kochite is found in the alkaline igneous complex of East Greenland and is named after Danish geologist

Geologist

A geologist is a scientist who studies the solid and liquid matter that constitutes the Earth as well as the processes and history that has shaped it. Geologists usually engage in studying geology. Geologists, studying more of an applied science than a theoretical one, must approach Geology using...

 Lauge Koch

Lauge Koch

Lauge Koch was a Danish geologist and Arctic explorer.He was the renowned leader of 24 Danish government expeditions to Greenland, and the central character in the Lauge Koch Controversy, an international and intra-national conflict...

 (1892-1964), a geologist who overturned the previous conception of Greenland's landscapes. Kochite is the titanium

Titanium

Titanium is a chemical element with the symbol Ti and atomic number 22. It has a low density and is a strong, lustrous, corrosion-resistant transition metal with a silver color....

 – manganese

Manganese

Manganese is a chemical element, designated by the symbol Mn. It has the atomic number 25. It is found as a free element in nature , and in many minerals...

 analog of rosenbuschite. It occurs 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...

 associated with nepheline

Nepheline

Nepheline, also called nephelite , is a feldspathoid: a silica-undersaturated aluminosilicate, Na3KAl4Si4O16, that occurs in intrusive and volcanic rocks with low silica, and in their associated pegmatites...

, alkali feldspar

Alkali feldspar

The alkali feldspar group are those feldspar minerals rich in the alkali elements like potassium. The alkali feldspars include: anorthoclase, microcline, orthoclase and sanidine....

, and låvenite in the Werner Bjerge alkaline complex along the eastern coast of Greenland

Greenland

Greenland is an autonomous country within the Kingdom of Denmark, located between the Arctic and Atlantic Oceans, east of the Canadian Arctic Archipelago. Though physiographically a part of the continent of North America, Greenland has been politically and culturally associated with Europe for...

.