Extra-Mantle Genetic Diamond Types and the Potential of the Kamchatka Diamondiferous Province of Russia.

This paper reports results from a study of two new genetic types of diamond discovered in Kamchatka. These diamonds were formed under extra-mantle conditions, as can be inferred from the fact that there is no indication of post-crystallization annealing with the formation of aggregated nitrogen defects in them. The first of these types is defined by us as volcanic-atmoelectrogenic. This is formed directly in a volcanic ash-gas cloud due to deep-seated methane released by atmospheric electric discharges. The second genetic type of diamonds is formed at depth within a magmatic-pneumatolytic-hydrothermal ore deposit, and can be defined as the explosive-tuffisite type. The industrial potential of these types enables us to assert the discovery of a new diamondiferous province, i.e., the Kamchatka Province. [ABSTRACT FROM AUTHOR]