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Entry № 277

Marcasite

Iron sulfide (orthorhombic)

Brassy cockscomb of quick clarity.

Chakra

Solar Plexus · Root

Element

Earth · Fire

Zodiac

Leo · Aries

Marcasite

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

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