Rock (Likely Sedimentary)

Sandstone

Arenite (primarily SiO2)

Mica-rich metamorphic rock, likely schist

Muscovite–biotite schist; principally muscovite mica, biotite, quartz, and feldspar

Chert (specifically Agate/Jasper variety)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Petrified Wood

Silicified Wood (SiO2)

Sandstone (likely Quartzose Sandstone)

Clastic Sedimentary Rock (primarily SiO2)

Jasper with Hematite inclusions

Silicon Dioxide (SiO2) with Ferric Oxide (Fe2O3)

Banded Sandstone

Clastic Sedimentary Rock (Quartz Arenite)

Fossiliferous Limestone

Limestone with embedded fossil cross-section

Chert

Microcrystalline Quartz (SiO2)

Limestone (River Pebble)

Calcium Carbonate (CaCO3)

Pyrite (on Shale/Matrix)

Iron Disulfide (FeS2)

Banded gneiss

Felsic biotite–quartz–feldspar gneiss

Pyrite-bearing schist (likely mica schist)

Muscovite–quartz schist with disseminated pyrite (FeS₂)

Sandstone

Arenite (composed primarily of SiO2)

Mixed rock and mineral collection

Multiple specimens; visible pieces may include quartz, calcite, agate/chalcedony, jasper, and dyed or coated materials

Weathered quartz-rich pebble (tentative)

Likely quartz/chalcedony, SiO₂, possibly iron-stained

Sandstone (Micaceous/Feldspathic variant)

Arenite (specifically subarkose or lithic arenite)

Iron-rich weathered rock, likely lateritic sandstone or ironstone

Ferruginous sandstone/ironstone; chiefly quartz (SiO₂) with hematite/goethite (Fe₂O₃·nH₂O)

Sandstone (likely Arkose or Quartz Sandstone)

Arenite (SiO2 + varied clasts)

Chert (or Ironstone Nodule)

Silicon Dioxide (SiO2) or Limonite-stained Cryptocrystalline Quartz

Chalcedony (Botryoidal/Agate nodule)

Microcrystalline Quartz (SiO2)

Granite Gneiss

Gneiss (High-grade metamorphic rock)

Turquoise

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

Sandstone (likely Quartz Sandstone)

Arenite (SiO2 based)

Banded gneiss (likely amphibolite-bearing gneiss)

Gneiss; quartz–feldspar–mica/amphibole aggregate

Banded Sandstone (River Cobble)

Arenite Sandstone with heavy mineral layering

Sandstone (likely Graywacke or Arkosic varieties)

Arenite (composed primarily of SiO2)

Weathered iron-rich rock, likely laterite or ironstone

Ferruginous laterite/ironstone, composed mainly of goethite (FeO(OH)), hematite (Fe₂O₃), and clay minerals

Granite boulder

Granite, composed mainly of quartz, alkali feldspar, plagioclase, and minor mica/amphibole

Sandstone (Stream-rounded Cobble)

Arenite (composed primarily of SiO2, Silica)

Reddish-brown rounded pebble, likely iron-stained sandstone or chert

Probable quartz-rich sandstone (SiO₂), possibly ferruginous chert; exact identification requires testing

Gneiss Pebble

Gneiss (High-grade metamorphic rock)

Agate (Chalcedony)

Cryptocrystalline Silica or Silicon Dioxide (SiO2)

Sandstone (likely Quartzose Sandstone)

Arenite (composed primarily of SiO2)

Chalcedony in Matrix (likely Agatized Coral or Chert)

Silicon Dioxide (SiO2)

Schist

Mica Schist

River Pebble (Gneiss or Granite)

Metamorphic Rock (likely Gneiss or Granitic composition)

Blue Opal in Matrix

Hydrated Silica (SiO2·nH2O)

Iron-rich chert or jasper pebble

Microcrystalline quartz (SiO₂), colored by iron oxides

Likely weathered quartz-rich rock, possibly smoky quartz or chert

Quartz (SiO₂), though exact identification is uncertain from the photograph

River Rock (likely Basalt or Greywacke)

Basalt or Lithic Sandstone

Chalcedony Nodule (Commonly known as Agate or Chert)

Microcrystalline Quartz (SiO2)