Lazurite

Species

Rare · Na₇Ca(Al₆Si₆O₂₄)(SO₄)(S₃)·H₂O

The deep blue mineral named for the colour of lapis lazuli, grown where limestone is baked by an intrusion. Its blue comes from the S₃ trisulfide ion caught in the cages of its structure. Most of the blue in lapis lazuli turns out, on analysis, to be a sulfur-rich haüyne; true lazurite, redefined by the IMA in 2021, is far rarer than the stone that gave it its name.

Identity

Formula
Na₇Ca(Al₆Si₆O₂₄)(SO₄)(S₃)·H₂O
Chemical class
Silicate
Mineral group
Hauyne, Lapis Lazuli, Sodalite
Crafting Table colours
Blue, Green

Crystallography

Crystal system
Cubic
Habits
Dodecahedral, Granular, Massive
Fracture
Uneven

Physical properties

Mohs hardness
5.5
Density
2.4 g/cm³
Luster
Vitreous
Colors
dark blue, blue, violet-blue, blue-green
Streak
blue
Transparency
Translucent, Opaque

Geology

Origins
Metamorphic
Host rocks
Marble
Associated minerals
Calcite, Pyrite, Diopside, Olivine, Hauyne, Mica
Found in
Lapis Lazuli, Skarn
Geography
Afghanistan (Sar-e-Sang), Russia (Lake Baikal), Tajikistan (Pamir), Italy (Monte Somma), Myanmar (Mogok), Chile

Classification

Rarity
Rare
Gem quality
No

Where to find it in Hearth

Rocks
Marble

Sources

Browse the Crystal Encyclopedia — MGS Toolbox