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Entry № 099

Chiastolite

Andalusite with Graphite Cross

The cross stone of protection.

Chakra

Root · Third Eye

Element

Earth

Zodiac

Libra

Chiastolite

I. The Metaphysical Reading

How the stone has been held.

Chiastolite is worked with as a stone of protection and passage, carried during travel, difficult conversations and the crossings between one chapter of life and the next. Practitioners hold it as a reminder that the symbol of the cross predates any single tradition and appears wherever pressure meets pattern.

Chakra
Root · Third Eye
Element
Earth
Zodiac
Libra
Keynote
The cross stone of protection.

II. The Scientific Reading

What the lattice actually does.

Chiastolite is a variety of andalusite (Al₂SiO₅) in which graphite impurities were pushed to the corners of the growing crystal during regional metamorphism, producing a distinctive dark cross visible in cross-section. Historically prized as a talisman across medieval Europe, it forms in low-pressure metamorphic aureoles around granite intrusions in schist and slate.

Formula
Al₂SiO₅ with graphite inclusions
System
Orthorhombic
Hardness
6.5 – 7.5 (Mohs)
Provenance
China, Spain, Chile, Russia, Australia, USA (California)

References & Sources

Independent mineralogical references used to verify the scientific details above.

Mineral Profile

Fact Sheet

Chemical Formula
Al₂SiO₅ with graphite inclusions
Crystal System
Orthorhombic
Mohs Hardness
6.5 – 7.5 (Mohs)
Density
3.10 – 3.20 g/cm³
Refractive Index
1.629 – 1.650
Provenance
China, Spain, Chile, Russia, Australia, USA (California)
Color Origin
Brown andalusite prisms with dark cross pattern in cross-section

Related Crystals

Stones that share this lattice

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Chinese Writing Stone

A stone that reads like a page.