Rock Identifier
Fossilized Dinosaur Skull (Tyrannosaurus rex) (Tyrannosaurus rex (permineralized fossil), rich in Hydroxylapatite/Silica) — sedimentary
sedimentary

Fossilized Dinosaur Skull (Tyrannosaurus rex)

Tyrannosaurus rex (permineralized fossil), rich in Hydroxylapatite/Silica

Hardness: 5-7 (depending on mineral replacement); Color: brownish-tan to black; Luster: dull to vitreous; Structure: retains the bone's original cellular morphology in a rock matrix.

Hardness
5-7 (depending on mineral replacement)
Color
brownish-tan to black
Luster
dull to vitreous
Identified More sedimentary

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Physical properties

Hardness: 5-7 (depending on mineral replacement); Color: brownish-tan to black; Luster: dull to vitreous; Structure: retains the bone's original cellular morphology in a rock matrix.

Formation & geological history

Formed via permineralization where minerals (like silica or calcite) precipitate into organic pores. This specimen appears to be from the Late Cretaceous period (approx. 66-68 million years ago).

Uses & applications

Scientific research, museum display, and high-end private collecting.

Geological facts

T. rex had one of the strongest bite forces of any terrestrial animal. Fossils like this are technically trace/body fossils preserved within sedimentary rock layers like the Hell Creek Formation.

Field identification & locations

Identified by the distinct therapod skull shape, large fenestrae (holes in skull), and serrated teeth. Found primarily in North American badlands.