fossil

Dinosaur Bone (Petrified/Agatized)

Permineralized Dinosauria Bone (Silicate Replacement)

Hardness: 6.5-7 (Mohs scale), Color: Mottled grey, white, and black tones with cellular patterns, Luster: Waxy to vitreous when polished, Structure: Microcrystalline quartz (chalcedony) replacing original bone structure, Cleavage: None.

Hardness: 6

Identified July 15, 2026More fossil →

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Physical properties

Formation & geological history

Formed through permineralization where groundwater saturated with dissolved silica seeped into buried skeletal remains, replacing biological material cell-by-cell with agate or jasper during the Mesozoic era (approx. 66-250 million years ago).

Uses & applications

Used in lapidary arts for cabochons, knife handles, and jewelry; also highly valued as a specimen for paleontological study and private fossil collections.

Geological facts

The distinctive 'cell' pattern visible on the cut surface is the original trabecular or cancellous bone structure preserved in stone. This specific look is often called 'Gembone' when the mineralization is colorful and translucent.

Field identification & locations

Identify by looking for the honeycomb or porous cellular texture typical of bone marrow. Commonly found in the Morrison Formation of the Western United States (Utah, Colorado, Wyoming). Collectors should look for distinct, unbroken cell walls.

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