M878 - Smithsonite, Mexico.

Small (About 3-1/2") $7.90
Medium (About 4" to 5") $12.00
Large (About 6") $16.50

Smithsonite is a Zinc carbonate, often with some iron. Hardness 4
to 4-1/2. Botroyoidal form specimens. These specimens are a whitish/gray color. Smithsonite is a secondary mineral and occurs chiefly in the oxidized zone of massive hydrothermal replacement deposits. It is associated with gelena, cerussite, azurite, and malachite.

Weights
Small: about 0.8 lbs.
Medium: about 1.5 lbs
Large: about 2.0 + lbs

From Mexico.