Wt: 1¼lbs (about 560g)
Sarany, Ural Mountain region, Russia
While I am describing this specimen as a millerite specimen, I am torn between several other good descriptions. The millerite is present as several isolated needles, plus a few sparse clusters of needle-like crystals, some of which are curved, and others are branched. The color is a rather metallic green. The next mineral is the largest volume, and is likely just a milky white calcite that has been smoothly etched away to reveal the minerals within. The largest area is a purple mineral sometimes organized in blades or balls (like barite), and sometimes in sprays of acicular crystals, and in some areas appears largely etched away like it might be mangano-calcite and was lost in an acid bath. Then one edge of the host rock looks like it is coated with a purple lepidolite, and finally part of the bottom looks like a silvery mica (perhaps just a very pale lepidolite).