Results are presented on the influence of the size of diamond powders
and the laser power on the main Raman line. These results show conclus
ively that there is a consistent and systematic, reversible, downshift
with both decrease of powder size, and increase of power. The shift c
an be explained by local heating of about 500 degrees C in the extreme
case. Its significance applies to interpretation of the alleged;''dow
nshifting'' of the 1332 cm(-1) Line in all diamond research. In the fu
ture, the grain size, the thermal contact, and the beam power must be
carefully monitored in reporting and interpreting any frequency shifts
.