Ottrelite

This is a ottrelite specimen from Ottrez, Belgium, the type locality for this rare mineral. It is a rich example, with dozens of sharp, black monoclinic crystals embedded in a schist-like phyllite matrix. Ottrelite, a manganese analogue of chloritoid, is rarely available on the market. Specimens from the type locality in Belgium are especially prized for their scarcity in mineral collections.