Zeolite

The name “zeolite” is derived from Greek words meaning “boiling stones” because the minerals frothed when heated to high temperatures. The reaction of alkaline groundwater with ash layers and volcanic rocks will produce the Zeolite naturally.

"Zeolite" is the group name for a large number of framework alumosilicates. 

Due to the natural variation in the minerals, the one you receive may not match the one in the photo.