sedimentary

Flint with Fossil Inclusion

Cryptocrystalline quartz (SiO2) enclosing fossilized organic remains

Hardness of 7 on the Mohs scale, grayish exterior with dark patches, waxy to vitreous luster, conchoidal fracture, microcrystalline quartz structure.

Identified August 7, 2026More sedimentary →

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Physical properties

Hardness of 7 on the Mohs scale, grayish exterior with dark patches, waxy to vitreous luster, conchoidal fracture, microcrystalline quartz structure.

Formed through the chemical replacement of limestone or chalk by silica-rich solutions in shallow marine environments during the Cretaceous period.

Historically used for making stone tools and fire-starting; today primarily collected as a geological specimen or used for lapidary work.

Flint nodules often form around organic nuclei such as sponges or shells, which can become fossilized within the stone.

Found commonly in chalk deposits and coastal gravel beds. Can be identified in the field by its characteristic conchoidal fracture and high hardness.

Sandstone or Siltstone

Arenite (if sandstone)

Fossiliferous Concretion

Septarian Concretion containing Brachiopods/Crinoids

Quartz pebble

Silicon dioxide (SiO2)

Generic Pebble / Rock Fragment

Lithic fragment / Weathered rock

Banded Siltstone / Mudstone Pebble

Siltstone / Argillite

Sedimentary Sandstone

Arenite (Sedimentary Rock)