Metamorphic (Likely Gneiss Or Schist Based On Texture)

Porphyritic Andesite

Andesite (Porphyry)

Aventurine (specifically Green Aventurine)

Silicon Dioxide (Quartz) with inclusions of Fuchsite; SiO2 + K(Al,Cr)2AlSi3O10(OH)2

Blue Apatite

Calcium Fluorophosphate (Ca5(PO4)3F)

Ferruginous Sandstone (Ironstone Nodules)

Ferruginous Quartz-Arenite (with Goethite/Hematite cement)

Vuggy Quartz on Matrix

Silicon Dioxide (SiO2)

Serpentinite (likely brecciated serpentinite)

Serpentinite; primarily serpentine-group minerals (antigorite, lizardite, chrysotile), commonly with magnetite, brucite, and relict olivine/pyroxene

Polished green aventurine (likely)

Quartzite dominated by quartz (SiO₂), commonly containing fuchsite mica

Serpentine (likely serpentinite)

Serpentinite; chiefly serpentine-group minerals (antigorite, lizardite, chrysotile), commonly with magnetite and chromite

Basalt with Quartz Vein

Basalt (SiO2 vein inclusion)

Unidentifiable Specimen

Undetermined

Mixed rock and mineral collection

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

Quartzite Pebble

Quartzite (primarily SiO2)

Conglomerate

Conglomeratic Sandstone / Polymictic Conglomerate

Weathered granite

Granite; quartz–feldspar–mica plutonic rock

Rounded quartz-rich pebble

Likely microcrystalline quartz (SiO₂), possibly milky quartz or a pale quartzite fragment

Weathered quartz-rich rock, likely milky quartz or quartzite

Quartz (SiO₂), possibly quartzite with iron-oxide staining

Greenstone / Diabase Porphyry

Porphyritic Diabase (Micro-gabbro)

Red Jasper (Siltstone or Chert-based Jasper)

Silicon dioxide with hematite (SiO2 + Fe2O3)

Mixed polished river pebbles, predominantly quartzite and quartz

Quartzite (SiO₂), quartz (SiO₂), with possible feldspar-rich and iron-stained lithologies

Amazonite

Microcline (K(AlSi3O8))

Green aventurine cabochon (likely)

Quartzite/aventurine quartz, predominantly SiO₂ with possible fuchsite mica

Schist with Schorl (Black Tourmaline)

NaFe3Al6(BO3)3Si6O18(OH)4 (Schorl)

Tumbled quartzite pebble

Quartzite, predominantly crystalline SiO₂

Sandstone Geode (Unbroken)

Siliciclastic sedimentary rock (primarily Quartz)

Quartzite Pebble (with Quartz Vein)

Meta-quartzite (SiO2-dominated metamorphic rock)

Quartzite Pebble

Quartzite (composed primarily of SiO2)

Sandstone (likely Greywacke or Lithic Sandstone)

Arenite / Wacke

Feldspar-rich Quartzite

Metamorphic Quartz-Feldspar Aggregate (SiO2 + KAlSi3O8)

Green Aventurine

Silicon Dioxide (SiO2) with Fuchsite inclusions

Yellow Quartzite (River Cobble)

Quartzite (mainly SiO2)

Rounded basalt cobble

Basalt, a fine-grained mafic volcanic rock composed mainly of plagioclase and pyroxene, commonly with olivine and iron oxides

Fluorite-Gedrite in Quartz (Schist)

Fluorite (CaF2) with Gedrite in Quartz/Feldspar Matrix

Likely basalt or other dark igneous rock

Basalt; predominantly plagioclase feldspar and pyroxene, possibly olivine

Chalcedony (Agate/Jasper mix)

Cryptocrystalline Sillimanite (Quartz) - SiO2

River Rocks and Pebbles

Mixed Silica-rich Sediments (SiO2 based)

Laterite

Lateritic Soil/Rock (rich in Fe2O3 and Al2O3)

Glaucophane Schist (Blueschist)

Blueschist facies metamorphic rock

Weathered quartz-rich rock, likely quartzite

Quartzite; predominantly crystalline SiO₂, possibly iron-oxide stained

Sandstone (Grooved/Weathered)

Arenite (composed primarily of Quartz and Lithic fragments)

Water and Silt (Sedimentary Environment)

Suspended Sediment / H2O (dihydrogen monoxide)

Sandstone (likely Graywacke or Arkose)

Clastic Sedimentary Rock (primarily SiO2 with various lithic fragments)

Sandstone (Water-worn Cobble)

Arenite (SiO2 with CaCO3 or Fe2O3 cement)