fossil

Agatized Dinosaur Bone

Permineralized Dinosaur Bone (Silicified/Agatized Bone)

Hardness: 6.5 to 7 on the Mohs scale (due to quartz replacement); Color: Varies widely including white, tan, brown, red, and occasionally blues or greens depending on mineral impurities; Luster: Waxy to vitreous; Structure: Microcrystalline quartz (chalcedony) replacing original cellular bone structure.

Hardness: 6
Luster: Waxy to vitreous

Identified July 28, 2026More fossil →

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Physical properties

Formation & geological history

Formed during the Mesozoic Era, primarily the Jurassic and Cretaceous periods (approx. 65 to 150 million years ago). Created when buried dinosaur remains had their organic bone material slowly replaced by silica-rich groundwater over millions of years.

Uses & applications

Prized by paleontologists, rockhounds, and lapidary artists for creating polished display specimens, cabochons, and custom jewelry.

Geological facts

The cellular structure of the bone is often perfectly preserved at a microscopic level even after being entirely turned to stone (quartz). Some rare specimens exhibit chatoyancy or include other minerals like jasper and opal.

Field identification & locations

Easily identifiable by the distinct honeycomb or web-like cellular bone pattern visible on the exterior or cross-section, coupled with the vitreous/waxy luster of chalcedony where fractured. Commonly found in regions like the Morrison Formation in the western United States.

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