I really enjoy collecting micro minerals.
A good definition of a micro mineral is a specimen that requires illumination and magnification to be appreciated. It is possible to put together a good collection, without too much expense (microscope purchase aside). Crystals can be more perfect than on larger specimens, and in many cases, rare minerals only occur in small sizes. And your whole collection can be housed in a relatively small space.
Because of their small size, it is not difficult to build up a collection of trading material. This can be used to swap with other collectors around the world. I recently received a small exchange package from a friend of mine, Mark Ascher of Tucson, Arizona. One of the specimens he sent is this unusual blocky wulfenite from the Fulton Mine in Pima County, Arizona.
Did I ever say how much I really enjoy collecting micro minerals?