Anthracite in fish tank?

Can you add anthracite to your fish tank?

I found 3 pieces, the largest being the size of a 50 cent piece, and I was wondering if I could put it in my 110 Gallon?

It holds african dwelling fish.

Being that its pretty much coal and carbon is refined coal I would say yes.
But being quite unsure of the full composition and never having done it myself I would say no

it should be fine just soak it for acouple of days