Entry № 277
Marcasite
Iron sulfide (orthorhombic)
Brassy cockscomb of quick clarity.
Chakra
Solar Plexus · Root
Element
Earth · Fire
Zodiac
Leo · Aries

I. The Metaphysical Reading
How the stone has been held.
Marcasite is worked with as a stone of sharp perception and unsentimental clarity. Its bright, brittle crystals are said to cut through illusion quickly, making it a stone for decisions that need to be taken now rather than deliberated.
- Chakra
- Solar Plexus · Root
- Element
- Earth · Fire
- Zodiac
- Leo · Aries
- Keynote
- Brassy cockscomb of quick clarity.
II. The Scientific Reading
What the lattice actually does.
Marcasite is an iron sulfide with the same chemistry as pyrite (FeS₂) but a different, orthorhombic crystal structure. It is less stable than pyrite and tends to alter to iron oxides and sulfuric acid over time, especially in humid conditions, giving specimens a characteristic tarnished bloom.
- Formula
- FeS₂
- System
- Orthorhombic
- Hardness
- 6 – 6.5 (Mohs)
- Provenance
- USA, Mexico, Czech Republic, France
References & Sources
Independent mineralogical references used to verify the scientific details above.
Mineral Profile
Fact Sheet
- Chemical Formula
- FeS₂
- Crystal System
- Orthorhombic
- Mohs Hardness
- 6 – 6.5 (Mohs)
- Density
- 4.85 – 4.90 g/cm³
- Refractive Index
- Opaque — metallic lustre
- Provenance
- USA, Mexico, Czech Republic, France
- Color Origin
- Pale brass yellow, tarnishing to grey-brown
Related Crystals
Stones that share this lattice
Next in the Atlas
Mariposite
Apple-green shimmer of the golden hills.




