Mineral Species: Petalite

Chemical Formula: LiAlSi4O10

Chemical Name: Lithium Aluminium Silicate 

Mineral Class: Tectosilicate

Mineral Notes: Petalite occurs in granite pegmatites. It is often mined locally as an ore of lithium. Its name comes from the Greek for leaf, reflecting its perfect basal cleavage.

Description: The mineral is highly crystalline but what makes the specimen is interesting is that the crystals are present in two colours. Those on top of the specimen are bluish-green whilst those in the lower half are significantly darker. They are embedded in a matrix of white Spodumene which provides an attractive contrast.

Location: Nova Ves, Kremze, Czech Republic.