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
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
Sources
- M. Pasero and others, IMA Commission on New Minerals, Nomenclature and Classification, The New IMA List of Minerals, updated September 2026. International Mineralogical Association (CNMNC), 2026.
- J. W. Anthony, R. A. Bideaux, K. W. Bladh, M. C. Nichols, Lazurite. Mineral Data Publishing, Handbook of Mineralogy, 2001.
- Lazurite. Mindat.org (Hudson Institute of Mineralogy).
- Lapis lazuli. Mindat.org (Hudson Institute of Mineralogy).
Browse the Crystal Encyclopedia — MGS Toolbox