Any grinder can handle whole Coriander and Cumin, dry roasted or straight out of the packet.
There all different in Aroma, freshly ground is stronger in flavour than pre ground bought packet powders.
Turmeric, Garlic and Ginger powders are ground superfine because they are not seed. a simple difference.
Anyhoo, the next time you use your coffee grinder to grind some whole Coriander seeds,
Have a look at the superfine powder gathered in the lid of the grinder, you couldn't wish for finer powder.
In fact it is that fine it becomes airborne, I found this out when I was grinding Birds Eye chillis for my Phall curries.
I opened the grinder and got a face full of hot chilli dust.
Eyes, Nose and Throat, sneezing all over the place, ouch!, :

lesson learnt.
cheers Chewy