silicates
Lazurite
Na7Ca(Al6Si6O24)(SO4)(S3)-·H2O
- Crystal system
- cubic
- Hardness
- 5–5.5 on the Mohs scale
- Lustre
- dull
- Colour
- Deep blue
- Where it forms
- In marbles altered by contact with igneous intrusions, in a small number of places worldwide.
- Chiefly from
- Sar-e-Sang, Badakhshan, AfghanistanLake Baikal, RussiaChile
Why it is that colour
Not a metal. The blue comes from trisulfur radical ions trapped inside cages in the aluminosilicate framework — an unusual mechanism, and the reason the colour is so intense and so stable.
Safety
Safe to handle.
Where it comes from
The Sar-e-Sang mines in Badakhshan have been worked for over six thousand years and are the source of nearly all historically significant lapis. Control of the mines has been a factor in Afghan conflict financing, documented by Global Witness in 2016.
Historical use
The blue in Tutankhamun’s mask, in Sumerian jewellery from Ur, and in the ultramarine of Renaissance painting is this mineral.
Recorded as history and attributed where possible. That a stone was used for something establishes that people used it, not that it worked.
What is attributed to it, and since when
Its history is the history of lapis lazuli, of which it is the blue component; see that entry. Lazurite as a distinct mineral name is nineteenth-century.
Described, not endorsed. Dating a claim is not the same as assessing it — but an association that first appears in a book published in 1985 is not an ancient inheritance, whatever the label says. A sincere account of feeling better is compatible with the stone doing nothing — see the placebo effect.
Worth knowing
Lazurite gets its own entry because the thing people buy is a rock and this is the mineral inside it. The colour mechanism is genuinely unusual: most mineral colour comes from transition metals like iron, copper or chromium, and this one comes from sulfur ions rattling around inside cages in the crystal structure. It is closer to how a dye works than to how a gemstone usually works.
Identity checked against IMA-CNMNC master list, June 2025.