Tissintite is a very rare variety of pyroxene originally discovered in the Tissint Martian meteorite. It is characterized by its significant vacancy in the M2 site of the crystal structure, making it a unique planetary mineral known primarily to researchers and high-end meteorite collectors.
Is this tissintite?
2-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch tissintite with a known reference. Tissintite sits at Mohs 6-7, softer than the next harder reference, harder than the previous one.
- 2Look at form & habitCrystal system: monoclinic. Typical habit: anhedral grains.
Often confused with
Tissintite vs. its common look-alikes, and how to tell them apart in the field.
All properties
- Chemical formula
- (Ca,Na,□)AlSi₂O₆
- Mohs hardness
- 6-7
- Density
- 3.32 g/cm³
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Anhedral grains
- Rarity
- Rare
- Uses
- Collector, Scientific research
- Host rock
- In maskelynite (shocked plagioclase) and is commonly observed included within, or in contact with, shock-melt pockets in a Martian meteorite
Where rockhounds find tissintite
Classic worldwide localities
- Tissint, Morocco
Field-hunting tip
Where it forms: In maskelynite (shocked plagioclase) and is commonly observed included within, or in contact with, shock-melt pockets in a Martian meteorite. If you start seeing maskelynite in float, you are in the right ground. Typical habit: anhedral grains. Train your eye for that shape before scanning the outcrop.



