Hydrolysis of beta-SiC powder in the ''hydrothermal'' pressure-tempera
ture regime (1.4 kbar at 800 degrees C) leads to a sharp Raman band at
1330 cm(-1). This suggests evidence for growth of diamonds under hydr
othermal conditions. However, X-ray diffraction studies and scanning e
lectron microscopy analysis do not provide the usual evidence for diam
onds. Instead, they reveal euhedral monodisperse quartz crystals and a
second acicular phase. It is possible that any diamond crystals are v
ery small, with sizes of the order of few nanometers. However, transmi
ssion electron microscopy analysis reveals that the whiskers are a sil
icon oxycarbide with an approximate composition of SiO1.6C0.2 and have
a width up to 100 nm and lattice imaging revealed 9.0 Angstrom spacin
gs.