Geologists discover new mineral in Tibet

0 Comment
 23 Aug 2013   Posted by admin


A new mineral discovered in 2009 has been officially approved by the International Mineralogical Association.
The cubic boron nitride, named qingsongite, was found in the mountains of southern Tibet, within chromium-rich rock of the paleo-oceanic crust that was subducted to a depth of 350km and recrystallised there at a temperature of about 2372 degrees Fahrenheit and pressure of about 118,430 atmospheres.
University of California, Riverside geologists Larissa Dobrzhinetskaya and Harry Green uncovered the new mineral, together with scientists at the Lawrence Livermore National Laboratory, the University of Maine and institutions in China and Germany.
“About 180 million years ago the rocks were returned back to shallow levels of the Earth by plate tectonic processes leading to the closure of the huge Paleo-Thethys ocean — an ancient Paleozoic ocean — and the collision
of India with the Asian lithospheric plate,” Ms Dobrzhinetskaya said.
“The uniqueness of qingsongite is that it is the first boron mineral that was found to be formed at extreme conditions in deep Earth.
“All other known boron minerals are found at Earth’s surface.” Cubic boron nitride was first created in a laboratory in 1957 and came to be known as an important technological material.
It is used for grinding hardened ferrous and superalloy materials, and is classified as a ‘super abrasive’, usually found in grinding wheels and coatings.
“Because its atomic structure bears resemblance to carbon bonds in diamond, it has high density and could be as hard as diamond,” the University of California stated.
“Qingsongite was named after Qingsong Fang (1939-2010), a professor at the Institute of Geology, the Chinese Academy of Geological Sciences, who found the first diamond in the Tibetan chromium-rich rocks in the late 1970s, and contributed to the discovery of four new mineral species.”