Man Made Composite (Lithified Equivalent Of Sedimentary)

Tumbled quartz-rich stone, possibly smoky quartz or chert

Uncertain; likely microcrystalline quartz, SiO₂

Sandstone

Arenite (composed primarily of SiO2)

Sandstone

Arenite

Graphite-rich schist (probable graphite flake)

Graphite (C) in graphitic schist; possibly graphite-bearing phyllite

Tiger Shark Fossil Tooth

Galeocerdo cuvier (fossilized)

Bivalve Internal Mold Fossil

Steinkern (Mollusca: Bivalvia)

Weathered limestone or calcareous concretion

Calcite-rich carbonate rock; chiefly calcium carbonate (CaCO₃)

Turquoise (likely stabilized or simulated Howlite)

CuAl6(PO4)4(OH)8·4H2O (Hydrous phosphate of copper and aluminium)

Fossiliferous Limestone

Calcium Carbonate (CaCO3) with Bioclasts

Weathered fossiliferous limestone, likely coral or shell fragment

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

Fossil oyster shell

Exogyra sp. or a related fossil oyster; largely calcitic shell (CaCO₃)

Weathered limestone or calcareous sandstone

Calcite-rich carbonate rock, chiefly CaCO₃; exact identification is uncertain from the image

Iron-rich sandstone or weathered laterite

Ferruginous sandstone; chiefly quartz (SiO₂) cemented by iron oxides/hydroxides

Weathered sandstone or quartzite cobble

Quartz-rich sandstone; possibly weakly metamorphosed quartzite

Fossiliferous limestone

Bioclastic limestone, primarily calcite (CaCO₃)

Fossiliferous limestone

Bioclastic limestone, composed chiefly of calcite (CaCO₃)

Rounded sandstone pebble

Quartz-rich sandstone (likely subarkose or quartz arenite)

Rounded river pebble, likely weathered sandstone or siltstone

Indeterminate clastic sedimentary rock; likely quartz-rich sandstone/siltstone

Weathered iron-stained stone, likely graywacke or altered sandstone

Indeterminate lithic fragment; probable quartz-rich sandstone/graywacke with iron-oxide staining

River Cobble (Quartzite or Sandstone)

Arenite or Meta-quartzite (SiO2 composition)

Fossilized Rugose Coral

Order Rugosa (Calcium Carbonate - CaCO3)

Sandstone (Quartzite texture)

Arenite (SiO2 secondary)

Sandstone

Arenite (SiO2 based)

Fossiliferous limestone, likely coralline or stromatolitic

Biogenic limestone; predominantly calcite (CaCO₃)

Chert (Flint/Jasper variety)

Microcrystalline Quartz (SiO2)

Weathered fossiliferous limestone or fossil fragment

Indeterminate bioclastic carbonate rock; likely calcite (CaCO₃) with fossil shell material

Polished fossiliferous limestone, likely crinoidal or coral limestone

Calcite (CaCO₃), fossiliferous carbonate rock

Mixed beach pebbles and shell fragments

Mostly carbonate rocks, likely limestone/calcarenite, with mollusk-shell bioclasts; exact species cannot be determined visually

Sandstone

Arenite (SiO2 based clastic rock)

Polished jasper–quartzite river pebble

Silicified metasedimentary rock, chiefly microcrystalline quartz (SiO₂) with iron-oxide staining

Sandstone (Ferruginous)

Arenite (primarily SiO2 with iron oxide cement)

Fossilized turtle shell or carapace

Testudines indeterminate; shell mainly fossilized calcium-carbonate bone (apatite)

Fossiliferous limestone concretion

Calcite-rich limestone (primarily CaCO₃), possibly containing a fossil shell or coral fragment

Probable weathered sandstone or iron-rich sedimentary rock

Indeterminate siliciclastic rock; likely quartz-rich sandstone with iron-oxide staining

Weathered sandstone or quartz-rich metasedimentary pebble

Likely quartz arenite (sandstone), possibly weakly metamorphosed; predominantly SiO₂ quartz with feldspar and iron-oxide cement

Calcite-rich limestone, possibly fossiliferous

Limestone composed mainly of calcite (CaCO₃), potentially containing a fragmentary fossil or calcite-filled structure

Ruby in Zoisite

Anyolite (composite of Corundum Al2O3 and Zoisite Ca2Al3(SiO4)(Si2O7)O(OH))

River Pebble (Granitic Sandstone)

Clastic sedimentary rock (Lithic Arenite)

Weathered shale or mudstone

Clastic mudrock, chiefly clay minerals, quartz, and feldspar

Fossiliferous Limestone (Hash)

Bioclastic Grainstone / Calcarenite

Weathered sandstone fragment

Sandstone, likely ferruginous quartz arenite or arkose

Weathered iron-rich sandstone or laterite fragment

Ferruginous sandstone, chiefly quartz (SiO₂) cemented or stained by iron oxides/hydroxides