Laumontite is a mineral of the zeolite group. Laumontite easily dehydrates when stored in a low humidity environment. When freshly collected, if it has not already been exposed to the environment, it can be translucent or transparent. Over a period of hours to days the loss of water turns it opaque white. In the past, this variety has been called leonhardite, though this is not a valid mineral species. The dehydrated laumontite is very friable, often falling into a powder at the slightest touch. Best keep it hydrated folks! Find more rare collector gemstones at

Laumontite, Freakingcat

Freakingcat Laumontite