An overview of vis-nir-swir field spectroscopy - Spectral International

________________________________________________________________
(reddish-black, irregular to octahedral crystal shape), and olivine (pale yellowgreen)
are the most commonly used kimberlite indicator minerals in drift
prospecting. Kimberlite indicator minerals are recovered from the medium to very
coarse sand-sized fraction of glacial sediments, and analyzed by electron
microprobe to confirm their identification.
(source: http://sts.gsc.nrcan.gc.ca/page1/miner/kirk/indic.htm)
Garnets
Pyrope, Almandine, Grossular
Diopside
Chrome-diopside, diopside
Others to consider
Zircon, Olivine, Orthopyroxenes (Harzburgite?),Chromite??, Ilmenite??,
Perovskite??
Figure 53 - This plot includes
almandine, grossularite, pyrope garnets;
diopside, Cr-diopside, and olivine. Figure 54 - Garnet comparisons
\
41
The indicator garnet for the presence of diamonds in
kimberlites is a G-10. This has a diagnostic chrome
feature in the visible, indicated by the arrow.