sedimentary
Pyritized Ammonite
Ammonitida (replaced by Iron Disulfide, FeS2)
Hardness: 6-6.5 (Mohs scale), Color: Brass-yellow or gold, Luster: Metallic, Crystal Structure: Isometric (replacement of organic spiral structure), Specific Gravity: 4.8-5.0
- Hardness
- 6-6
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Physical properties
Hardness: 6-6.5 (Mohs scale), Color: Brass-yellow or gold, Luster: Metallic, Crystal Structure: Isometric (replacement of organic spiral structure), Specific Gravity: 4.8-5.0
Formation & geological history
Formed during the Jurassic or Cretaceous periods in oxygen-poor marine environments where bacteria produced hydrogen sulfide that reacted with iron to replace the shell with pyrite.
Uses & applications
Highly valued for fossil collections, decorative display, and metaphysical jewelry.
Geological facts
Ammonites are extinct cephalopods related to modern squids and octopuses. Pyritization occurs only under very specific chemical conditions in the ocean floor sediment.
Field identification & locations
Identified by its distinctive spiral shape and metallic gold sheen. Commonly found in locations like the Jurassic Coast of England or the Volga River in Russia.
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