Mineral (Tectosilicate)

Sandstone

Arenite (SiO2 based)

Quartz with Mineral Inclusions

Silicon Dioxide (SiO2)

Yellow iron-oxide-rich mineral/rock fragment

Likely limonite/goethite (hydrated iron oxides; commonly approximated as FeO(OH)·nH₂O)

Sandstone with Manganese Dendrites

Clastic Sedimentary Rock (SiO2 based with MnO2 inclusions)

Weathered fossil bone fragment (identification uncertain)

Fossilized bone; exact taxon and mineral composition cannot be determined from the image

Porphyritic volcanic rock, likely porphyritic andesite

Porphyritic andesite (feldspar phenocrysts in a fine-grained groundmass); visual identification is tentative

Polished pink feldspar-rich rock, possibly unakite

Likely unakite (epidote, pink potassium feldspar, and quartz); identification is uncertain from the photo

Schist

Mica Schist

Tumbled granite pebble

Granite, a quartz–feldspar plutonic rock

Limonite (Ironstone)

Limonite (FeO(OH)·nH2O)

Polished granite pebble

Granite, a coarse-grained felsic plutonic rock composed mainly of quartz, feldspar, and mica

Clear quartz crystal (tentative)

Quartz, silicon dioxide (SiO₂)

Tumbled brown quartz (likely smoky quartz)

Quartz, silicon dioxide (SiO₂); brown coloration may be smoky quartz or iron-stained quartz

Tumbled quartz pebble, likely iron-stained milky quartz

Quartz (SiO₂), possibly with iron-oxide staining

Dark green mineral specimen, possibly serpentine or epidote

Tentatively serpentine-group mineral, Mg₃Si₂O₅(OH)₄, or epidote, Ca₂(Al,Fe)₃Si₃O₁₂(OH)

Rhodochrosite

Manganese Carbonate (MnCO3)

Limonite (Iron Ore)

Limonite (FeO(OH)·nH2O)

Polished agate with possible iron-oxide inclusions

Microcrystalline quartz (chalcedony), SiO₂; inclusions appear to be iron oxides, possibly goethite or hematite

Fluorite

Calcium fluoride (CaF2)

Small blue mineral specimen, possibly sodalite

Sodalite, Na₈(Al₆Si₆O₂₄)Cl₂ (tentative identification)

Biotite-bearing granite (likely granodiorite)

Coarse-grained granitoid, composed mainly of quartz and feldspar with dark biotite or hornblende

Pink-and-white granite

Granite, a coarse-grained felsic intrusive igneous rock; typically quartz, feldspar, and mica

Speckled feldspar-rich pebble

Likely leucocratic granite or granitic pegmatite, chiefly potassium feldspar with dark biotite or amphibole

Amygdaloidal Basalt

Amygdaloidal Basalt (containing quartz/agate or zeolite fill)

Granite

Intrusive Igneous Rock

Rough garnet-bearing rock (likely almandine garnet in host rock)

Garnet, probably almandine (Fe₃Al₂(SiO₄)₃), in a garnet-bearing metamorphic matrix

Weathered copper-bearing rock, possibly chrysocolla-bearing quartz or host rock

Indeterminate from the photo; possible chrysocolla (hydrated copper silicate) with quartz or other host minerals

Milky Quartz with Mica Matrix

SiO2 (Silicon Dioxide) with Muscovite/Biotite mica

Prehnite

Prehnite (Ca2Al2Si3O10(OH)2)

Polished greenstone (likely serpentine)

Serpentinite; chiefly serpentine-group minerals, Mg₃Si₂O₅(OH)₄

Possible fossilized bone fragment

Indeterminate vertebrate bone; no taxonomic identification is possible from the image alone

Malachite

Malachite (Cu2CO3(OH)2)

Milky Quartz

Silicon Dioxide (SiO2)

Malachite

Copper Carbonate Hydroxide (Cu2CO3(OH)2)

Shale

Shale (clastic sedimentary rock)

Mica-rich schist (likely biotite schist)

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

Coarse-grained dark igneous rock, probably diorite

Diorite (tentative; exact identification requires closer examination)

Likely amphibolite

Amphibolite, composed mainly of hornblende (amphibole) and plagioclase feldspar

Gneiss (Cobble)

Gneiss

Banded Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

Chrysocolla

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

Likely rough amethyst (purple quartz)

Quartz, SiO₂; purple coloration typically caused by trace iron and natural irradiation