Kimberlite garnets rich in chromium, are generally absent from most other igneous rocks, making them particularly useful as indicators for kimberlites. These indicator minerals are generally sought in stream sediments in modern alluvial material. Their presence may indicate the presence of a kimberlite within the erosional watershed that produced the alluvium. The geochemistry of Kimberlites is defined by the following parameters: Kimberlites are the most important source of primary diamonds. Many kimberlite pipes also produce rich alluvial or eluvial diamond placer deposits. About 6,400 kimberlite pipes have been discovered in the world, of those about 900 have been classified as diamondiferous,
Tianshan Volcanic Group Chinese army) said that when climbing the Tianshan Mountains, saw "The Fire Mountains which send out masses of molten rock which flow for many Li" Tianshan Volcanic Group The Tianshan Volcanic Group is a volcanic field in the Tianshan Mountains in Northwest China. The historically active Cone of Pechan is within the group (also known as Peishan, Baishan, Hochan, Aghie, Bichbalick, Khala, and Boschan). The volcano is 440 km southwest of Urmqui, Xinjiang. Two eruptions are known from Tianshan, in 50 AD (± 50 years)and 650 AD (± 50 years). The book, Aspects of Nature in Different Lands and Different