Mineral

Mixed rock and mineral collection

Unidentified assortment of geological specimens; individual species cannot be determined from the image

Tumbled quartz pebble, likely iron-stained milky quartz

Quartz (SiO₂), possibly with iron-oxide staining

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)

Porphyritic volcanic rock, likely porphyritic andesite

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

Weathered fossil bone fragment (identification uncertain)

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

Polished pink feldspar-rich rock, possibly unakite

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

Schist

Mica Schist

Yellow iron-oxide-rich mineral/rock fragment

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

Polished greenstone (likely serpentine)

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

Tumbled brown quartz (likely smoky quartz)

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

Iron-stained quartz vein in altered host rock

Quartz (SiO₂) with iron oxides/hydroxides, likely hematite and goethite; host rock uncertain from the image

Dark green mineral specimen, possibly serpentine or epidote

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

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)

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)

Likely rough amethyst (purple quartz)

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

Purple amethyst crystal specimen

Amethyst, purple variety of quartz (SiO₂)

Small blue mineral specimen, possibly sodalite

Sodalite, Na₈(Al₆Si₆O₂₄)Cl₂ (tentative identification)

Clear quartz crystal (tentative)

Quartz, silicon dioxide (SiO₂)

Quartz-rich pegmatite fragment

Granite-family pegmatite; chiefly quartz (SiO₂), feldspar, and black mica (biotite)

Pink potassium feldspar (orthoclase/microcline)

KAlSi₃O₈; likely massive potassium feldspar, possibly with quartz

Likely gneiss

Quartz–feldspar–mica gneiss (visual identification is uncertain)

Weathered greenstone (probable)

Chlorite–actinolite–epidote metamafic rock; exact identification requires testing

Likely dyed or painted stone

Unidentified natural rock; vivid purple, orange, and pink coloration appears to be a surface coating or pigment, so the underlying rock cannot be reliably identified from the image.

Greenstone (likely chlorite-rich metamorphic rock)

Chlorite-rich greenschist; commonly composed of chlorite, actinolite, and epidote

Small dark rock fragment (unidentified)

Undetermined; composition cannot be identified reliably from this photograph

Dark, speckled coarse-grained rock; likely diorite

Diorite, an intrusive igneous rock composed mainly of plagioclase feldspar and hornblende or other dark minerals

Calcite (commonly referred to as Orange Calcite or Honey Calcite given its color)

Calcite

Black Sand (Magnetite/Heavy Mineral Concentrate)

Magnetite-rich Placers (Fe3O4)

Tumbled serpentine (likely green serpentinite)

Serpentine-group minerals, commonly antigorite, lizardite, or chrysotile; serpentinite is the rock

Sandstone with Ironstone Concretion

Arenite with Ferruginous Cement

Rhodochrosite with Quartz

Manganese Carbonate (MnCO3) with Silicon Dioxide (SiO2)

Turquoise

Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)

Pegmatite

Igneous Pegmatite