Chert
Chert gives little or no decrepitation at all, in contrast to most
vein quartz and this can be useful to discriminate between them. The
Cosmo
Howley and Enterprise are gold mines hosted in proterozoic sediments in
NT, Australia and the Victory gold mine is hosted in Archaen
greenstones
near Kalgoorlie, WA. In each mine the cherts are easily discriminated
from
the gold bearing quartz veins using decrepitation. In theory, mapping
should
permit recognition of these sample types, but in practice many
misclassifications
of the samples have occurred, highlighting the need for a technique
such
as decrepitation. One sample of ore bearing vein quartz from the
Victory
mine is included for comparison. Note also the prominent low
temperature
peak on this sample, caused by CO2 rich inclusions.
Location map of Australian deposits