GENESIS OF NATURAL DIAMONDS ACCORDING THE DATA OF EXPERIMENTAL INVESTIGATIONS. Samoilovich M.I., Petrovsky V.A., Shilov Yu.A., Pechorskaya St. 58 Syktyvkar, 167005, Russia.

The presence of inclusion of silicate minerals itself in natural diamonds does not gurantee that the growth of the crystals took place in silicate melt so long as the latter could fulfil the functions of surroundings. The many types of inclusions in diamonds are iron - and nickel - containing minerals (metals) which transformation in sulphureous and oxide compounds is the result of their following evolution.

Nitrogen admixture is rounded up growing crystal, but in the consequence in the result of such solid solution complexes form beginning from some nitrogen atoms (often with carbon vacancies) and including lamellar accumulations-platelites consisting of tens and hundreds of nitrogen atoms. Main part of natural diamonds passed the process of thermobaric treatment, i.e. annealing at high pressure and temperature (possible in interim nidus, but P, T-parameters are less than the growing ones).

In nature diamonds growed like synthetic ones i.e. surrounded thin filmof melt consisting of mainly iron, nickel manganese, cobalt and partly chromium. The main demands to such metals which are dissolvents of carbon, consist of absence of stable carbide and good enough carbon dissolubility.