Star shaped Arsenopyrite twins as inclusion in Quartz from Dodo.
Arsenopyrite from Dalnegorsk
While polishing a dunite rock sample from Nizhne Tagil, I discovered these blocky crystals.
I thought they might be platinum.... Thanks to the analytical effort of prof Jacques Jedwab I
now know these are arsenopyrite crystals with microscopic galena inclusions.
[photo's/collection: Maurice de Graaf]