Sedimentary And Igneous

Weathered schist or gneiss boulder

Micaceous quartz-feldspar schist/gneiss; exact identification is limited by the photograph

Red Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Likely weathered schist or gneiss fragment

Micaceous quartz-feldspar metamorphic rock; exact identification requires testing

Weathered schist or gneiss cobble

Foliated silicate rock, likely mica schist or biotite gneiss

Biotite-bearing gneiss or schist

Quartz–feldspar–mica metamorphic rock, likely mica schist/gneiss

Rounded metamorphic pebble, likely mica schist or gneiss

Mica schist/gneiss; commonly quartz, feldspar, and biotite or muscovite mica

Gneiss

Gneiss

Dark metamorphic rock, likely biotite schist or gneiss

Quartz–feldspar–biotite metamorphic rock; exact identification requires a fresh surface and testing

Mixed River Stones and Minerals

Mixed Silica-rich Stones (Quartz, Agate, Jasper, Sandstone, Dalmation Stone)

Red Jasper

Silicon Dioxide (SiO2) with Hematite inclusions

Likely garnet-bearing schist or gneiss

Mica schist/gneiss containing quartz, feldspar, mica, and probable almandine garnet

Weathered quartz-mica schist

Quartz–muscovite/biotite schist, locally iron-oxide stained

Silver-colored mica schist

Muscovite–quartz schist, possibly with biotite

Banded Gneiss / Metamorphic River Pebble

Gneiss (Foliated Metamorphic Rock)

Gneiss (Gneissic Granite Pebble)

Metamorphic rock rich in Quartz, Feldspar, and Mica

River Pebble (Gneiss / Granitic Schist)

Metamorphic Rock (Quartz-Feldspar-Mica assembly)

Jasper

Jasper (Silicon Dioxide, SiO2 plus iron oxide impurities)

Weathered metamorphic rock, possibly schist or gneiss

Indeterminate; likely quartz–feldspar–mica rock, potentially greenschist or gneiss

Quartz-bearing metamorphic rock, likely schist or quartzite

Quartz (SiO₂) in a mica-rich metamorphic matrix

Weathered metamorphic rock, likely mica schist or gneiss

Quartz–feldspar–mica schist/gneiss; exact identification is uncertain from the photograph

Biotite mica schist (probable)

Schist dominated by biotite mica; commonly quartz–feldspar–biotite

Quartz–mica schist or mica-rich quartzite

Quartz with muscovite/biotite mica; likely a quartz-mica schist, possibly pegmatitic

Weathered quartz-bearing metamorphic rock

Likely quartz–feldspar schist or gneiss, possibly with iron-oxide alteration

Pyrite-bearing schist or quartzite

Micaceous quartz-rich metamorphic rock with pyrite (FeS₂)

Tourmaline-rich schist (likely black tourmaline)

Schist containing schorl, Fe-rich NaFe3Al6(BO3)3Si6O18(OH)4

Mica-bearing metamorphic rock, likely schist

Muscovite/biotite mica schist with quartz and feldspar

Banded metamorphic river cobble, likely gneiss or metasedimentary rock

Quartz–feldspar–mica gneiss or quartzite with cross-cutting quartz veins

Likely raw mica-bearing metamorphic rock or mineral fragment

Tentatively biotite schist; visually similar dark mica-rich material

Raw garnet-rich metamorphic rock

Likely garnet-bearing schist or garnetite; garnet-group silicates, commonly almandine (Fe₃Al₂Si₃O₁₂)

Likely foliated metamorphic rock (quartz-mica schist or gneiss)

Quartz–feldspar–mica metamorphic rock; exact identification requires a fresh surface and tests

Garnet-bearing metamorphic rock, likely garnet schist or amphibolite

Almandine garnet (Fe₃Al₂Si₃O₁₂) in mica- or amphibole-rich matrix

Quartz–mica metamorphic rock, likely schist

Quartz–muscovite/biotite schist; predominantly SiO₂ quartz with phyllosilicate micas

Folded Schist / Gneiss (Metamorphic Rock)

Regional Metaphoric Folded Outcrop (predominantly Schist/Gneiss)

Biotite-bearing metamorphic rock, likely schist

Mica schist; chiefly quartz, feldspar, and biotite mica

Quartz on Matrix

Silicon Dioxide (SiO2)

Red Jasper (Opaque Chalcedony)

Silicon Dioxide (SiO2) with Hematite (Fe2O3) inclusions

Quartz-bearing metamorphic rock, likely garnet-mica schist

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

Druzy Quartz on Host Rock

Silicon Dioxide (SiO2) with various iron-oxide inclusions

Quartz (likely Jasper or Chert variety)

Quartz (SiO₂)

River Stone (likely Siltstone or fine-grained Basalt)

Clastic Sedimentary (Siltstone) or Mafic Igneous (Basalt)

Mixed Rock Collection

Polylithic Geological Specimen Mix

Geode half

Geode (often quartz/chalcedony based)