Mineral Species: Heulandite

Chemical Formula: (Ca,Na2)Al2Si7O18.6(H2O)

Chemical Name: Hydrous Calcium-Sodium Aluminium Silicate

Mineral Class: Zeolite Silicate

Mineral Notes: Heulandite is a particular sub-class of tectosilicate known as a Zeolite. Zeolites are hydrated aluminium-rich silicates which can be dehydrated and hydrated without destroying their structure.

Description: Very bright and lustrous crystals of white Heulandite on matrix. These have a very pronounced pyramidal shape and sharp terminations. A very attractive display specimen.

Location: Kozákov, Liberec, Bohemia, Czech Republic.