hardness is 3-4, and the specific gravity 2.2. Heulandite is similar to stilbite. The two minerals may, however, be readily distinguished by the fact that in heulandite the acute positive bisectrix of the optic axes emerges perpendicular to the cleavage.

Discovery and occurrence

Heulandite was first separated from stilbite by August Breithaupt in 1818, and named by him "euzeolite" (meaning beautiful zeolite); independently,

1.Previous
3.Next