Neill Ridgley

Ankerite is interesting and surprisingly uncommon carbonate, mostly limited to metasomatic rocks and hydrothermal veins. It can form outstanding crystals and clusters.

Marcasite is very common mineral, but it is often ignored by mineral collectors. Despite its nice crystal forms, it lacks the luster of some other sulfides and its quite brittle. Its infamous instability in just slightly wet air does not help its popularity either.