Minerals identify

Know how to recognize them

Heulandite

Zeolites )

Heulandite is the name of a series of tecto-silicate minerals group. Prior to 1997, heulandite was recognized as a mineral species, but a reclassification in 1997 by the International Mineralogical Association changed it to a series name, with the mineral species being named: * Heulandite-Ca * Heulandite-Na * Heulandite-K * Heulandite-Sr * Heulandite-Ba (described in 2002).

Heulandite-Ca, the most common of these, is a hydrous calcium and aluminium, (Ca,Na) 2-3Al 3(Al,Si) 2Si 13O 36·12H2O. Small amounts of sodium are usually present replacing part of the calcium. Strontium replaces calcium in the heulandite-Sr variety. The appropriate species name depends on the dominant element. The species are visually indistinguishable, and the series name heulandite is still used whenever testing has not been performed.

Identification

Mohs scale ( mineral hardness )

3.5
4

The streak

White

Crystal ( diaphaneity )

Monoclinic