Mixed: Igneous And Sedimentary

River gravel and cobbles

Mixed alluvial clasts, likely including granite, basalt, quartzite, and sandstone

Conglomerate

Conglomerate (clastic sedimentary rock)

Quartz-bearing feldspar pegmatite (likely with mica/tourmaline)

Granitic pegmatite; chiefly quartz (SiO₂) and feldspar, with dark mica or tourmaline

Granite pebble

Granite; primarily quartz, alkali feldspar, plagioclase, and dark mica/amphibole

Polished/rounded granite cobble

Granite, chiefly quartz (SiO₂), feldspar, and mica/amphibole

Iron-rich sandstone or ferruginous conglomeratic sandstone

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

Conglomeratic sandstone / breccia-like gravel rock

Polymictic conglomerate (possibly lithified gravel or concrete-like natural conglomerate)

Polished quartz-rich feldspar rock, possibly orbicular granite

Granite or granitic pegmatite; chiefly quartz (SiO₂), feldspar, and dark biotite/amphibole

Tumbled banded stone, likely gneiss or granite

Quartz–feldspar rock, possibly banded gneiss; exact identification requires testing

Granite (Pink/Red)

Phaneritic Igneous Rock (Rich in K-Feldspar)

K2 Jasper (K2 Granite)

Azulite in Granite (Quartz + Feldspar + Biotite + Azurite)

Conglomeratic gravel / lithified alluvial deposit

Polymictic conglomerate or pebble-rich sandstone (likely weakly cemented)

Epidote (Unakite variety)

Epidosite (Metasomatic rock containing Ca2(Al,Fe)3(SiO4)3(OH))

Barite

Barium Sulfate (BaSO4)

Quartz-rich rock fragment

Likely milky quartz with feldspar and possible mica; exact rock type is indeterminate from the image

Granite or Granitoid River Rock

Granite

Granite Pegmatite

Pegmatite (Quartz, Feldspar, Mica)

Ironstone Pebble

Ferruginous sedimentary rock (Fe2O3 / FeO(OH) mixed with SiO2)

Unidentified coarse-grained rock fragments

Likely granite or granitic rock; exact identification is uncertain from the photograph

Feldspar (Granite Pegmatite matrix)

Potassium Feldspar (KAlSi3O8) / Quartz Mixture

Polymict conglomerate

Clastic conglomerate, likely polymictic pebble conglomerate

Weathered limestone or calcareous concretion

Calcite-rich limestone; predominantly calcium carbonate (CaCO₃)

Conglomerate

Conglomerate (Clastic sedimentary rock)

Mixed River Stones and Agates

Mixed Silicates and Ironstones (primarily SiO2 and Fe2O3)

Mixed rough mineral specimens, likely calcite with prehnite/zeolite

Calcite (CaCO₃), with probable prehnite (Ca₂Al₂Si₃O₁₀(OH)₂) and/or zeolite-group minerals

Fossiliferous Shale Matrix

Clastic Sedimentary Rock with Brachiopod or Mollusk shell fragments

Granite

Granite (Phaneritic intrusive igneous rock)

Conglomerate

Conglomerate (Sedimentary rock containing rounded clasts)

Sandstone (likely Greywacke or Siltstone variety)

Arenite / Siltstone (primarily SiO2)

Tumbled pink granite or feldspar-rich pebble

Granite; chiefly quartz (SiO₂), feldspar, and minor mica, though the specimen may be pink orthoclase feldspar

Granite Pebble

Granite

Gabbro

Gabbro

Conglomeratic volcanic breccia

Lithic volcanic breccia, likely andesitic or basaltic

Pink Granite

Phaneritic Felsic Igneous Rock (composed primarily of K-Feldspar, Quartz, and Plagioclase)

Amygdaloidal Basalt

Amygdaloidal Mafic Volcanic Rock

Rhyolitic Tuff

Rhyolitic Tuff / Pyroclastic rock

Chrysocolla on Matrix

Hydrated copper silicates ((Cu,Al)2H2Si2O5(OH)4·nH2O)

Concrete Paver (Artificial Cementitious Rock)

Hydrated Portland Cement Aggregate

Conglomerate

Conglomerate (clastic sedimentary rock)

Tumbled granite

Granite, a coarse-grained felsic intrusive igneous rock

Weathered granite

Granite, a coarse-grained felsic intrusive igneous rock

Weathered granite pebble

Granite, a quartz–feldspar–mica plutonic rock