Kimberlite (rare Russian locality piece)

Item Description

This is a distinctive and rare kimberlite specimen fragment from a 8-9 cm in diameter circular core from a well-known Russian diamond pipe with numerous xenoliths or fragments of other rock/mineral types in the kimberlite matrix. Kimberlite is an igneous rock best known for sometimes containing diamonds. Kimberlite occurs in the Earth's crust in vertical structures known as kimberlite pipes as well as igneous dykes and sills. Kimberlite pipes are the most important source of mined diamonds today. The consensus on kimberlites is that they are formed deep within the mantle. Formation occurs at depths between 150 and 450 kilometres (93 and 280 mi), potentially from anomalously enriched exotic mantle compositions, and they are erupted rapidly and violently, often with considerable carbon dioxide and other volatile components (Wikipedia). Seldom on the market. Ex St. Mockel Collection and the James Howard Collection (a well known Arkansas geologist and collector, formerly State Geologist).