Rock Identifier
Agate with Fossil Bone (Silicified bone in Chalcedony (SiO2)) — fossil
fossil

Agate with Fossil Bone

Silicified bone in Chalcedony (SiO2)

AI-generated identification · may be incorrect

Hardness of 6.5 to 7 on the Mohs scale, waxy to vitreous luster, cryptocrystalline structure, displaying a mix of grey chalcedony and porous orange-brown fossilized bone material.

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Physical properties

Hardness of 6.5 to 7 on the Mohs scale, waxy to vitreous luster, cryptocrystalline structure, displaying a mix of grey chalcedony and porous orange-brown fossilized bone material.

Formation & geological history

Formed through permineralization where groundwater rich in silica replaced original organic bone material with chalcedony over millions of years.

Uses & applications

Prized by lapidaries and fossil collectors as a unique display specimen and for custom cabochons in jewelry.

Geological facts

These specimens represent a rare geological overlap where dinosaur or prehistoric mammal bones are completely agatized, preserving cellular structure within quartz.

Field identification & locations

Identify by contrasting textural patterns between the smooth translucent chalcedony matrix and the porous, cellular bone structure. Commonly found in gravel beds and ancient river terraces in regions like the western United States.

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