Richterite

Real mineral · rare · Na(CaNa)(Mg,Fe++)₅[Si₈O₂₂](OH)₂

A sodium calcium amphibole of metamorphosed limestone and manganese deposits, running from brown to a deep translucent blue when potassium takes a place in the structure.

Identity

Formula
Na(CaNa)(Mg,Fe++)₅[Si₈O₂₂](OH)₂
Chemical class
silicate
Mineral group
Actinolite, Hornblende, Tremolite

Crystallography

Crystal system
monoclinic
Habits
prismatic, fibrous, bladed
Fracture
uneven

Physical properties

Mohs hardness
6
Density
3.09 g/cm³
Luster
vitreous
Colors
blue, brown, brown red, gray violet, yellow
Streak
white
Transparency
transparent, translucent

Geology

Origins
metamorphic, hydrothermal
Host rocks
marble, skarn
Associated minerals
Calcite, Tremolite, Diopside
Geography
Sweden, USA, India

Classification

Rarity
rare
Gem quality
No

Browse the Crystal Encyclopedia — MGS Toolbox