The piece comes from Poona, India and is 6 inches across. Mesolite is a mineral in the category called zeolites, a kind of silicate less stable than quartz. The fineste zeolites in the world come from rock quarries in the Bom bay-Poona regions of India. This specimen was obtained from Dr. J. Zaveri in Bombay. It comes from Elbingerode in the Harx mountains of Germany.
Calcite is quite a common mineral, yet desirable for collectors.
Usually, it is not very expensive, and it occurs in a number of crystal forms and in many colors. Calcite may be opaque, as it is here, or transparent. The main crystal in the illustrated group is twinned, which lends a special character to the piece.