Sedimentary (Biogenic Sediment Or Biological Remain)

Polished dark stone, likely basalt or black jasper

Basalt (fine-grained plagioclase–pyroxene rock), possibly iron-rich jasper/chert

Fossiliferous limestone

Calcite-rich limestone (primarily CaCO₃), possibly containing fossil fragments

Weathered limestone pebble

Calcite-rich limestone (predominantly CaCO₃); exact identification is uncertain from the image alone.

Weathered chert or siliceous limestone

Microcrystalline quartz (SiO₂), possibly replacing or cementing carbonate rock

Oyster Shell (Aragonite/Calcite)

Calcium Carbonate (CaCO3)

Fossil Shell in Sedimentary Matrix

Bivalvia (fossil) in Calcium Carbonate Matrix

Fossil gastropod shell

Spiral marine gastropod fossil; likely a small ammonite-like or gastropod shell, exact taxon indeterminate

Polished brown chert or jasper pebble

Microcrystalline quartz (SiO₂), likely chert/jasper

Weathered fossiliferous limestone, likely coral or shell fragment

Calcite (CaCO₃), biogenic limestone; exact fossil taxon indeterminate from the image

Hag Stone (Holey Rock / Fossiliferous Limestone)

Limestone (CaCO3) with natural erosion / fossil cavities

Flint or chert fragment

Microcrystalline quartz (SiO₂), commonly chalcedony with possible iron-oxide impurities

Polished fossil tooth, likely shark tooth

Likely fossilized shark tooth; exact taxon cannot be determined from this image

Chert nodule in sandstone or iron-stained host rock

Microcrystalline quartz (SiO₂), likely chert/flint

Porous fossil fragment (possibly fossilized coral or shell)

Unidentified fossil carbonate; likely calcite/aragonite

Kidney Stone (Calcium Oxalate / Uric Acid)

Calcium Oxalate Monohydrate (Whewellite) / Calcium Oxalate Dihydrate (Weddellite)

Fossiliferous Rock (Invertebrate Fossil in Matrix)

Fossiliferous limestone or shaly matrix containing skeletal fossil remains

Fossilized shell or coral fragment

Likely silicified or calcitic marine invertebrate fossil; exact taxon indeterminate from the image

Petrified Wood

Silicified Wood (primarily SiO2 - Silicon Dioxide)

Fossil oyster shell

Fossilized bivalve, likely Ostrea or Crassostrea; calcite (CaCO₃) shell

Silicified oyster fossil

Fossil oyster shell, commonly Ostrea or Crassostrea, replaced or encrusted by chalcedony/quartz

Fossil shell fragment

Indeterminate molluscan bioclast, likely aragonite or calcite

Chert or flint fragment

Microcrystalline quartz (SiO₂), likely chert/flint

Banded Chert Pebble

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Bivalve Fossil (Clam)

Class Bivalvia, likely Mercenaria or similar genus

Yellow chert or jasper pebble

Microcrystalline quartz (SiO₂), likely iron-oxide-stained chert/jasper

Weathered iron-rich chert or jasper

Microcrystalline quartz (SiO₂), commonly colored by iron oxides/hydroxides

Flint (chert), likely a worked or fractured nodule

Microcrystalline quartz/chalcedony (SiO₂)

Brown chert or flint pebble

Microcrystalline quartz (SiO₂), commonly with chalcedony and iron-oxide staining

Fossil Shark Tooth

Chondrichthyes dentition (Fossilized Tooth)

Shell Cameo

Cypraecassis rufa (Bullmouth Queen Helmet Shell)

Hag Stone (Banded Chert or Limestone with Borehole)

Microcrystalline Quartz (Chert) or Calciferous Siltstone (CaCO3/SiO2)

Worn quartz-rich pebble

Likely microcrystalline quartz (SiO₂), possibly a weathered chert or milky quartz fragment

Limitation Concretion

Ironstone Concretion (Goethite/Limonite)

Fossilized Shark Tooth

Chondrichthyes (Class)

Tumbled brown chert or jasper pebble

Microcrystalline quartz (SiO₂), likely chert/jasper

Fossilized bivalve shell

Fossil mollusk, likely an oyster or similar cemented bivalve; original shell mostly calcite (CaCO₃)

Fossiliferous shale or mudstone with plant fossils

Carbonaceous mudstone/shale containing fossilized foliage, likely fern or seed-fern impressions

Fossil Bivalve Shell

Class Bivalvia (e.g., Veneriidae family)

Small fossilized tooth, possibly a shark tooth

Indeterminate fossil tooth; species cannot be identified from this image

Chert or microcrystalline quartz fragment

Chert; cryptocrystalline SiO₂, possibly chalcedony-rich

Tumbled dark flint/chert

Microcrystalline quartz (SiO₂), commonly with chalcedony and iron-oxide impurities

Fossiliferous Limestone (Coquina / Shell Limestone)

Biogenic Limestone (Calcium Carbonate, CaCO3)