Marble

Hematite

Ferric oxide (Fe2O3)

Chert (Light Grey / Flint variant)

Cryptocrystalline Quartz (SiO2)

Milky Quartz Pebble

Silicon Dioxide (SiO2)

Chert (Nodule)

Chert (Alpha-Quartz, SiO2)

Chert (varieties include Flint and Jasper)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Shale (with minor calcite veining)

Clastic sedimentary rock (primarily clay minerals and quartz)

Sandstone (likely Quartzose Sandstone with mineral staining)

Arenite (composed mainly of SiO2)

Chert

Chert (Microcrystalline Silica, SiO2)

Coquina

Bioclastic Limestone

Fossil Shell (Bivalve)

Phylum Mollusca, Class Bivalvia (typically composed of Calcium Carbonate / CaCO3)

Rough Diamond

Diamond (pure Carbon, C)

Limestone (specifically fossiliferous/skeletal limestone)

Calcium Carbonate (CaCO3)

Hag Stone

Perforated Sedimentary Rock (typically Limestone or Sandstone)

Chert (varieties include Jasper or Flint)

Chert (Microcrystalline Silica, formula: SiO2)

Jasper (specifically Chert/Ironstone)

Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions

Chert (Brecciated River Cobble)

Silicon Dioxide (SiO2)

Coquina

Biogenic Limestone (Calcite/Aragonite)

Banded Chert (River Stone/Cobble)

Microcrystalline Quartz (SiO2)

Crushed Limestone

Calcite-rich Sedimentary Rock (CaCO3)

Coquina

Bioclastic Limestone (CaCO3)

Fossiliferous Limestone (Coquina / Shell Conglomerate)

Bioclastic Limestone (composed primarily of CaCO3)

Fossilized Oyster Shell

Gryphaea or Crassostrea fossil (Calcium Carbonate, CaCO3)

Brachiopod Fossil (Spiriferid)

Order Spiriferida (Phylum Brachiopoda); mineralized as Calcite (CaCO3) or Chert (SiO2)

Chert (Jasper/Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (specifically Flint)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Ironstone (Limonitic Shale)

Ferruginous Siltstone / Goethite-rich Sedimentary Rock

Beach Quartzite Pebble

Quartzite (primarily SiO2)

Chert (with Quartz veins)

Microcrystalline Quartz (SiO2)

Sandstone

Arenite (primarily SiO2)

Chert (with Lichen)

Microcrystalline Quartz (SiO2)

Baltic Amber

Succinite (Polmerized conifer resin)

Red Chert (Jasper)

Silicon Dioxide (SiO2)

Limestone

Calcium Carbonate (CaCO3)

Serpentine

Antigorite / Lizardite / Chrysotile (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4

Limestone

Calcium Carbonate (CaCO3)

Chalk

CaCO3 (primarily Calcium Carbonate), biogenic sedimentary rock

Fossiliferous Limestone (Crinoidal)

Calcite-bearing bioclastic packstone (CaCO3)

Diamond

Diamond (pure carbon C)

Coquina

Biogenic Limestone (Coquina)

Yellow Diamond (Faceted)

Diamond (C - Pure Carbon)

Sandstone (Ferruginous)

Arenite (Fe-rich)

Yellow Calcite

Calcium Carbonate (CaCO3)