2013

Experimental growing model of fibrous diamond crystals

Afanasyev V.P., Chepurov A.I., Sonin V.M.

Institute of Geology and Mineralogy, SB RAS, Russia, Novosibirsk

avp-diamond@mail.ru

There are two known base growth mechanism for natural diamonds – lamellar or tangential in situation of low saturation in carbon, and fibrous or normal in condition of oversaturation by carbon. We obtained an experimental confirmation for the second case. A growth apparatus became disconnected during the standard procedure of high quality diamond crystal growing and the system was undergone of rapid cooling. As a result a fully black opaque diamond crystals composed by subparallel pillar subindivides oriented by <111>  were formed (Fig.1).  A pillar heads are composed by octahedral and rhombododecahedral faces, and the last is presented in equal role with octahedral faces or predominate in the face complex.

Fig. 1. A diamond crystal had grow up on the seed under rapid cooling.

Appearance of rhombododecahedral faces, low quality of crystal and its pillar morphology can be explained as a result of rapid growth in conditions of significant oversaturation of carbon and presence some amounts of water and hydrocarbons in the system.