11 - Kimberlite

Hello friends, Welcome to the Rock Repository at the Department of Geology, Shivaji Science College, Nagpur. I am Kimberlite, an ultrabasic igneous rock and a rare variant of peridotite located in Wajrakarur, Anantapur district, Andhra Pradesh. I am most commonly known to be the main host for diamonds in the rock matrix. I  was named after the town of Kimberly in South Africa. I have a porphyritic texture, with large, often rounded crystals phenocrysts of olivine, chrome diopside, pyrope garnet, chrome spinel, and magnesian ilmenite surrounded by a fine-grained matrix groundmass of clinopyroxene, phlogopite, and chlorite. My structures are emplaced as carrot-shaped, vertical intrusions termed pipes and igneous dykes occur as horizontal sills. I am formed deep within the mantle at depths between 150 and 450 kilometers or more. I am classified in the form of facies, namely crater, diatreme, and hypabyssal rocks. In India, kimberlite and associated clans of rocks lamproite and lamprophyre occur in the Panna district, Madhya Pradesh, famous for its active mine at Majagaon Lamproite/kimberlite pipe. My second occurrence is well known in Wajrakarur, Anantapur district, Andhra Pradesh. Thank you for visiting.