Sedimentary And Igneous

Mica-rich rock, likely mica schist

Mica schist, composed chiefly of muscovite and/or biotite with quartz and feldspar

Green Aventurine

Silicon Dioxide (Quartz with Fuchsite inclusions), SiO2

Gneiss

Metamorphic Gneiss (High-grade regional metamorphism)

Biotite-rich schist (probable)

Mica schist, likely biotite–quartz–feldspar schist

Rough garnet-bearing metamorphic rock

Likely garnet amphibolite or garnet-bearing schist; garnet-group silicate, commonly almandine (Fe₃Al₂Si₃O₁₂)

Weathered quartz-bearing metamorphic rock, likely mica schist or gneiss

Quartz–feldspar–mica assemblage; exact mineral identification requires testing

Quartz Geode

Crystalline Silicon Dioxide (SiO2) in Geode form

Mixed rock and mineral specimen collection

Mostly undetermined from the photograph; apparent quartz-rich rocks, sandstone, granite/gneiss, and possibly iron-oxide-bearing specimens

Red Garnet (likely Almandine or Pyrope)

Garnet group: X3Y2(SiO4)3 (e.g., Almandine: Fe3Al2Si3O12)

Red Jasper

Silicon Dioxide (SiO2) - variety of Chalcedony

Mica-rich schist (probable)

Mica schist, composed mainly of mica minerals with quartz and possibly feldspar

Likely garnet-bearing metamorphic rock

Garnet amphibolite or garnet-bearing schist; chiefly almandine garnet (Fe₃Al₂Si₃O₁₂) with amphibole, mica, and quartz

Polished garnet-bearing metamorphic rock

Likely garnet mica schist or garnet-bearing gneiss; garnet is commonly almandine, Fe₃Al₂(SiO₄)₃

Garnet-bearing schist or gneiss

Garnet-mica schist/gneiss; chiefly quartz, feldspar, mica, and almandine–pyrope garnet

Polished garnet-bearing gneiss

Biotite-quartz-feldspar gneiss with almandine garnet (garnet: Fe₃Al₂(SiO₄)₃)

Fluorite

Fluorite (Calcium Fluoride, CaF2)

Likely weathered metamorphic rock (possibly schist or gneiss)

Indeterminate; probable mica-rich quartz–feldspar metamorphic rock

Weathered metamorphic rock, likely schist or gneiss

Quartz–feldspar–mica metamorphic rock; exact identification requires testing

Quartz vein in foliated metamorphic rock

Likely quartz-bearing schist or gneiss; visible crystal is quartz (SiO₂)

Quartz-veined metamorphic rock, likely schist or gneiss

Quartz–feldspar–mica rock; exact identification requires testing

Banded Gneiss Pebble

Gneiss (Metamorphic Rock)

Quartz Geode

Silicon Dioxide (SiO2)

Fluorite

Calcium Fluoride (CaF2)

Geode

Silicon Dioxide (Quartz/Chalcedony) in carbonate or volcanic host rock

Foliated metamorphic rock, likely schist

Mica schist (likely quartz–mica schist; exact identification requires closer examination)

Weathered quartz-rich metamorphic rock, likely gneiss or quartzite

Quartz (SiO₂)-bearing gneiss; exact identification requires a fresh surface and tests

Banded Gneiss

Gneiss

Banded metamorphic rock, likely schist or gneiss

Foliated quartz–feldspar–mica rock; exact mineral identification requires sampling

Garnet-bearing metamorphic rock, likely garnet gneiss or garnet amphibolite

Garnet-bearing gneiss; red crystals likely almandine garnet, Fe₃Al₂(SiO₄)₃

Weathered quartz-bearing metamorphic rock, likely gneiss or quartzite

Quartz-rich gneiss/quartzite with feldspar, mica, and iron-oxide alteration

Quartz Vein in Schist

Quartz-rich Micaceous Schist (SiO2 + phyllosilicates)

Weathered quartz-rich metamorphic rock, likely gneiss or schist

Quartz–feldspar–mica gneiss/schist (tentative; image resolution limits certainty)

Weathered, quartz-rich metamorphic rock (likely schist or gneiss)

Quartz–feldspar–mica schist/gneiss, with surface lichens and iron-oxide staining

River Stone (Chalcedony/Jasper variety)

Microcrystalline Quartz (SiO2)

Biotite-rich schist (mica schist)

Mica schist, chiefly biotite (K(Mg,Fe)₃AlSi₃O₁₀(OH,F)₂), with possible quartz and feldspar

Weathered quartz-rich metamorphic rock (probable gneiss or quartzite)

Biotite–quartz–feldspar gneiss, possibly micaceous quartzite

Biotite-rich schist (likely mica schist)

Mica schist; predominantly quartz, biotite mica, and feldspar

Garnet-bearing gneiss

Biotite–garnet gneiss, typically quartz + feldspar + biotite + almandine garnet

Weathered schist or gneiss

Quartz–feldspar–mica metamorphic rock

Gneiss

Gneissic Metamorphic Rock

Likely quartz fragment

Quartz (silicon dioxide, SiO₂)

Tumbled green aventurine

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