fossil

Fossilized bone

Petrified bone; commonly fossil vertebrate bone composed largely of hydroxyapatite and silica/calcite replacement minerals

AI-generated identification · may be incorrect

Dense, tan-brown, porous material with a bone-like cellular structure and dark mineral-filled cavities; hardness typically about 4–6 Mohs, dull to slightly waxy luster, and no prominent cleavage. The shape and texture suggest a fossil bone fragment rather than ordinary rock.

Identified September 11, 2026More fossil →

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Physical properties

Formation & geological history

Originally biological bone, later buried and mineralized through permineralization and replacement by silica, calcite, or iron oxides in sediment. Age cannot be determined from the image; such specimens range from thousands to hundreds of millions of years old.

Uses & applications

Collected as a fossil and used for educational display, lapidary work, and occasionally jewelry or polished cabochons. Scientific value depends on secure locality and identification.

Geological facts

The visible pores may represent remodeled bone tissue and vascular spaces filled with secondary minerals. Iron oxides likely produce the orange-brown coloration.

Field identification & locations

Identify by lightweight-looking but dense porous structure, irregular vascular channels, and continuity of the bone form; a fresh broken surface may show cellular patterns. Common in sedimentary fossil beds worldwide, especially the western United States, Madagascar, and Australia.