Komatiite Komati River [15711] South Africa

This is a great komatiite specimen from this exceedingly rare geological location. It has fantastic spinifex textured bladed olivine, which is prominent and easily seen. (The "spinifex" texture is named after an Australian grass that grows in clumps with similar shapes). In addition, this komatiite specimen has a polished front face.

Komatiite is a rare igneous, ultramafic, mantle-derived rock from volcanic origin. Komatiites have low silicon, potassium, and aluminum and high magnesium content. Komatiite was named for its specific type locality, where it is found along the Komati River, Weltevreden Formation, South Africa. This specimen is from the Pioneer Ultramafic Complex, Weltevreden Formation, Barberton, South Africa.

True komatiites are extremely rare to find on Earth. The age restriction (3.8 to 2.8 Ga) is thought to be due to the cooling of the mantle, which scientists believe may have been up to 500 degrees C hotter during the early to middle Archean. The early Earth had much higher heat production due to the residual heat from planetary accretion and a greater abundance of radioactive elements.

Geographically, komatiites are restricted in distribution to Archean shield areas. The pristine volcanic mineralogy of komatiites is composed of forsteritic olivine with chromian pyroxene, anorthite, and chromite. 

Komatiites are associated with nickel and gold deposits in Australia, Canada, South Africa, and most recently in the Guiana Shield of South America.

Specimen size: 32mm L X 24mm W X 20mm D; Weight: 18.5 grams. XRF Included. 

Ships with Certificate of Authenticity, tag, tag stand, protective box, and information about the specimen. Acrylic stand and sizing cube not included.

Komatiite is one of the more important geological materials for the serious rock collector.

Legally obtained in a materials trade with a scientific institution.