Rock Identifier
Obsidian and Fossilized Shark Tooth (Obsidian (Volcanic Glass) and Otodus sp. (Fossilized shark tooth)) — igneous and fossil
igneous and fossil

Obsidian and Fossilized Shark Tooth

Obsidian (Volcanic Glass) and Otodus sp. (Fossilized shark tooth)

AI-generated identification · may be incorrect

Obsidian: Hardness 5-6, black, vitreous/glassy luster, amorphous structure, conchoidal fracture. Shark tooth: Hardness ~5, tan/brown, serrated edges, enameloid surface.

Identified More igneous and fossil →
Explore Obsidian and Fossilized Shark Tooth in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App StoreGoogle Play

Physical properties

Obsidian: Hardness 5-6, black, vitreous/glassy luster, amorphous structure, conchoidal fracture. Shark tooth: Hardness ~5, tan/brown, serrated edges, enameloid surface.

Formation & geological history

Obsidian forms from the rapid cooling of silica-rich lava. The fossilized tooth is a biological remain from the Cenozoic or Mesozoic era that underwent permineralization in a marine environment.

Uses & applications

Obsidian is used for surgical blades, jewelry, and decorative objects. Shark teeth are primary items for fossil collection and jewelry.

Geological facts

Obsidian fractures produce edges thinner and sharper than steel scalpels. Fossilized shark teeth are found because sharks lose thousands of teeth throughout their lives.

Field identification & locations

Identify obsidian by its glassy texture and sharp, curved edges. Identify fossil shark teeth by their triangular shape and presence of serrations or root structures. Commonly found in volcanic regions and coastal sediment deposits.

More like this

Other igneous and fossil specimens

Fossiliferous limestone (Bioclastic limestone, commonly crinoidal or shelly limestone (calcite, CaCO₃)) — sedimentary

Fossiliferous limestone

Bioclastic limestone, commonly crinoidal or shelly limestone (calcite, CaCO₃)

sedimentary
Fossiliferous limestone (reef or shell-rich limestone) (Bioclastic calcarenite/calcirudite; predominantly calcite (CaCO₃)) — sedimentary

Fossiliferous limestone (reef or shell-rich limestone)

Bioclastic calcarenite/calcirudite; predominantly calcite (CaCO₃)

sedimentary
Fossilized bivalve shell fragment (Fossil Mollusca, likely a pectinid or related bivalve; exact identification requires the other shell half and locality) — fossil

Fossilized bivalve shell fragment

Fossil Mollusca, likely a pectinid or related bivalve; exact identification requires the other shell half and locality

fossil
Fossiliferous limestone, likely coral or shell-rich fragment (Calcite (CaCO₃), commonly bioclastic limestone containing fossilized marine organisms) — fossil

Fossiliferous limestone, likely coral or shell-rich fragment

Calcite (CaCO₃), commonly bioclastic limestone containing fossilized marine organisms

fossil
Weathered limestone or calcareous sandstone (Calcitic carbonate rock, likely limestone (CaCO₃), possibly slightly dolomitic) — sedimentary

Weathered limestone or calcareous sandstone

Calcitic carbonate rock, likely limestone (CaCO₃), possibly slightly dolomitic

sedimentary
Fossil coral limestone (Fossilized colonial coral, commonly tabulate or rugose coral in calcite-rich limestone (CaCO₃)) — fossil

Fossil coral limestone

Fossilized colonial coral, commonly tabulate or rugose coral in calcite-rich limestone (CaCO₃)

fossil