Mineral (Biogenic)

Fossiliferous Limestone

Biogenic Sedimentary Rock / CaCO3 with fossil fragments

Beach Pebbles and Quartz Aggregates

Quartz pebbles and biogenic fragments (SiO2, CaCO3)

Fossiliferous Limestone

Biogenic Sedimentary Rock (Calcium Carbonate, CaCO3)

Fossiliferous Limestone

Calcium Carbonate (CaCO3) matrix with biogenic fragments

Coquina

Biogenic Limestone (mostly Calcium Carbonate, CaCO3)

Fossiliferous Limestone (Coquina / Shell Limestone)

Bioclastic Limestone (CaCO3)

Brown chert or flint pebble

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

Flint (chert), likely a worked or fractured nodule

Microcrystalline quartz/chalcedony (SiO₂)

Tumbled dark stone, possibly chert or basalt

Indeterminate; likely fine-grained basalt (plagioclase–pyroxene) or microcrystalline chert (quartz, SiO₂)

Popcorn

Zea mays everta (P. Wilson) (Botanical name for the corn variety)

Calcite

Calcite (Calcium Carbonate, CaCO3)

Pearls (likely freshwater cultured pearls)

Pearl: nacre, primarily aragonite (CaCO₃) with conchiolin

Calcite (likely a tumbled specimen)

Calcite (CaCO 3 )

Sea Shell (Fighting Conch Fragment)

Calcium Carbonate (CaCO3) - Strombus alatus fragment

Weathered quartz-rich rock, likely chert or quartzite

Quartzite/chert; predominantly microcrystalline quartz (SiO₂), with iron-oxide staining and possible minor feldspar or clay minerals

Limestone (Chalk / Calcite Rock)

Calcium Carbonate (CaCO3)

Pearl-embellished decorative cross

Pearl (biogenic calcium carbonate, predominantly aragonite) with rhinestone-mounted glass or synthetic gemstones

Flint (chert), likely brown flint

Microcrystalline quartz/chalcedony (SiO₂)

Black flint (chert)

Microcrystalline quartz/chalcedony (SiO₂)

Rounded reddish-brown pebble, likely iron-stained quartzite or chert

Quartzite (mostly SiO₂), possibly ferruginous chert

Rounded flint or chert pebble

Microcrystalline quartz (SiO₂), commonly chalcedony with possible impurities

Chalky limestone

Micritic calcite (CaCO₃), likely biogenic limestone/chalk

Jasper containing fossilized inclusions

Silicon Dioxide (SiO2) with trace impurities and biogenic inclusions

Chalk

CaCO3 (primarily Calcium Carbonate), biogenic sedimentary rock

Pearl necklace

Pearl (biogenic calcium carbonate, chiefly aragonite; CaCO₃)

Fossiliferous Limestone

Biogenic Sedimentary Rock (primarily CaCO3 with fossil fragments)

Limestone with Calcite Veining

Calcium Carbonate (CaCO3) - Biogenic/Chemical Sedimentary Rock

Calcite

Calcite (CaCO₃)

Coral limestone / fossil coral

Biogenic calcium carbonate, chiefly aragonite or calcite (CaCO₃); likely fossilized colonial coral

Chert (or Flint)

Chert (cryptocrystalline quartz), SiO2

Flint

Chert (a form of cryptocrystalline quartz, chemical formula SiO₂)

Seashell fragment

Calcium carbonate (CaCO3)

Calcite

Calcite (CaCO3)

Fossilized cylindrical shell or bone fragment

Indeterminate biogenic carbonate or phosphatic fossil; possible fragment of a tubular shell (e.g., scaphopod) or hollow bone

Amber Inlay Jewelry

Fossilized Resin (C10H16O)

Chert

Chert (microcrystalline quartz, SiO2)

Chert (or possibly Flint)

SiO2 (Silicon Dioxide)

Pebble (likely Quartz or Chert)

SiO₂ (Silicon Dioxide) - referring to the likely main mineral composition, Quartz. If it's chert, the scientific name remains SiO₂ with a microcrystalline structure.

Chert (Jasper or Flint variant)

Chert (composed of microcrystalline quartz, SiO2)

Banded Iron Formation (BIF) with potential Stromatolite/Biogenic Trace

Ferruginous Chert / Banded Iron Formation (BIF)

Cockle Shell (Fossil or Recent)

Class Bivalvia, Family Cardiidae (e.g., Cerastoderma edule for common cockle)

Bivalve Shell (Fossil or Contemporary)

Class Bivalvie (various genera and species of clams, cockles, etc.)