Tumbling diamonds

Dear Peter,

The diamond rough from alluvial sources can be rounded because of
weathering. The best way to ascertain whether what you own may
contain diamonds is to get them identified from a gem lab or from a
certified gemologist.

Hoping that your glassy samples are a good find…!!!

All the best,

The diamond rough from alluvial sources can be rounded because of

I doubt that it’s weathering; more likely it’s a tumbling action.


I don’t know of any easy way to tell a micro-diamond 1/2 mm wide or
less from other glassy material.

I wouldn’t be so interested except these samples are from a fast
moving mountain river which “tumbles” loose stones over miles of
outcroppings and they seem to carry C as volcanic soot. The jet
black powder I have found in some poly-metallic veins is soot in a
"bubbly" host rock and I assume it is C soot.

I googled on the Wawa Ontario diamond find. That is from the last
decade and the host rock is not kimberlite. The area was thoroughly
prospected since the 1800s when some gold mines were started there.
So diamonds are the prospecting needle in the haystack.

If I cannot find a quick and easy assay method here, I may send them
to the DeBeers lab at U of A. Probably nothing but why not find out
for sure? They are of course studying the micro-diamonds from the
kimberlites in Northern Alberta.



One limitation on grease tables for diamond recovery is that it
works only on diamond freshly released from matrix, not on alluvial
diamond. So it would not necessarily work for you. Also, on a small
scale you might be looking for tiny fragments utterly submerged in a
much, much greater volume of grease, so you would need an elaborate
set of solvents and filters to separate the diamonds, if any. Perhaps
even a centrifuge to concentrate any solids in your solvents. Good

Dick Davies