The Popigai Crater about 100 km in size was formed ~36 my ago as a result of impact of asteroid ~4-6 km in size with the Earth in Northern Siberia. The target was Archean crystalline rocks of the North-Eastern part of the Anabar Shield enriched in graphite. Graphite at the edge of the crater was transformed during the impact event (P ~ 120-150 GPa and T ~ 3000-4000°C at the epicenter) into nanopolycrystalline material composed by variable amounts of the cubic diamond and hexagonal diamond (lonsdaleite) with the crystallite sizes ~ 30-70 nm. Potential resources of impact diamonds in the Popigai Crater are huge and are measured by trillions of carats. The technological characteristics of impact diamond are very impressive and significantly better those for synthetic diamonds: 1) 2-2.5 times higher processing speed of superhard materials (abrasive ability); 2) 2-3 times higher wear resistance; 3) 200-250°C higher heat resistance (thermal stability); 4) their specific surface is 0.7-0.8 m2/g, which is 8-9 times higher than that for synthetic diamonds, which contributes to good retention of impact diamonds when compacted with various binders. These characteristics determine high efficiency of use of the impact diamonds in wide range of modern technologies where existing characteristics of synthetic and convectional natural diamonds are insufficient. So, the basic principle of use of impact diamonds is replacement of synthetic and conventional natural diamonds in appropriate technologies with maximum technological and economic benefits.
Nikolay Pokhilenko born October 7, 1946 in Siberia, Russia. Graduated in 1970 from Novosibirsk State University (MSc in Geology) and began working at the Institute of Geology and Geophysics of the Siberian Branch (SB) of the USSR Academy of Sciences: Research Engineer; 1973 – Junior Researcher; 1977 – Senior Researcher; 1985 – Head of Diamond Laboratory. In 2006 – Deputy Director and 2007 – 2017 – Director of the Sobolev Institute of Geology and Mineralogy of the SB of the RAS; 2013 - till now – Vice-Chairman (Earth Sciences) of the SB of the RAS; 2017 – till now Scientific Director of the Sobolev Institute of Geology and Mineralogy, SB of the RUS. N.P. Pokilenko worked ~1.5 years at Geophysical Laboratory, Carnegie Institution of Washington, DC; and being an experienced field geologist he also worked during 41 field seasons in Arctic areas of Siberia (28 - in 1969-2012) and Northern Canada (13 in 1994-2006).
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