Sedimentary Or Igneous (Host Environment)

Quartz River Pebble

Silicon Dioxide (SiO2)

Limestone

Sedimentary rock composed primarily of Calcite (CaCO3)

Quartz in Matrix

Silicon Dioxide (SiO2) in host rock matrix

Small quartz-rich rock fragment (possibly weathered quartz vein material)

Quartz (SiO₂) in an undetermined host rock; the image is insufficient to identify the host confidently

Diabase (Dolerite)

Mafic intrusive igneous rock

Shale with Limonite/Hematite Staining

Argillaceous sedimentary rock with Iron Oxides (FeO(OH)·nH2O / Fe2O3)

Quartz Druzy (on Matrix)

Silicon Dioxide (SiO2)

Goethite pseudomorph after Pyrite

Goethite (FeO(OH)) pseudomorph after Pyrite (FeS2)

Fairburn Agate

Cryptocrystalline Quartz (SiO2) with trace Iron Oxides

Quartz with Schorl (Black Tourmaline)

Silicon Dioxide (SiO2) with Sodium Iron Aluminum Borosilicate (NaFe3Al6(BO3)3Si6O18(OH)4)

Quartz Geode Fragment

Silicon Dioxide (SiO2)

Jasper (Iron-rich)

Silicon Dioxide (SiO2) with Fe2O3 (Hematite) impurities

Geode (Chert or Quartz Nodule)

Silicon Dioxide (SiO2)

Blue Apatite

Apatite (Group), Ca5(PO4)3(F,Cl,OH)

Veined Quartzite / Vein-filled Sedimentary Rock

Siliciclastic rock with iron oxide-filled fractures

Pyrite-bearing sulfide specimen

Pyrite (FeS₂), possibly with chalcopyrite and weathered sulfides

Milky Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

River Rock with Quartz Vein

Basalt or Andesite with Quartz Veining

Bull Quartz

Quartz (Silicon Dioxide, SiO2)

Quartz Geode

Silicon Dioxide (SiO2) in a sedimentary host

Limestone

Calcium Carbonate (CaCO3)

Banded gneiss pebble

Gneiss, typically quartz–feldspar–mica assemblage

Blue Apatite

Apatite (Ca5(PO4)3(F,Cl,OH))

Green Aventurine

SiO2

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Quartz-bearing metamorphic rock, likely garnet-mica schist

Quartz–mica schist with probable garnet and iron-oxide minerals

Dendrite (Manganese Oxide Dendrites)

Psilomelane or Pyrolusite on Matrix (typically MnO2)

Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Turquoise

Turquoise (Hydrated phosphate of copper and aluminium), CuAl6(PO4)4(OH)8·4H2O

Honey calcite (likely rough calcite crystal)

Calcite, calcium carbonate (CaCO₃)

Concretion

Sedimentary Concretion (Ironstone / Calcite Concretion)

Small pale stone, possibly quartz or limestone

Indeterminate from image; likely quartz (SiO₂) or calcite-rich limestone (CaCO₃)

Jasper with Quartz Vein

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Quartz (Translucent/Rose variety)

Silicon Dioxide (SiO2)

Almandine Garnet

Iron aluminum silicate (Fe3Al2(SiO4)3)

Granite River Rock

Intrusive igneous rock (composed mainly of quartz, alkali feldspar, and plagioclase)

Quartz Vein in Gneiss/Granite

Silicon Dioxide (SiO2) in Feldspar-Quartz Gneiss host rock

Dark river-worn stone, likely basalt

Basalt; fine-grained mafic volcanic rock composed mainly of plagioclase, pyroxene, and commonly olivine

Milky Quartz

Silicon Dioxide (SiO2)

Chert (with Lichen)

Microcrystalline Quartz (SiO2)