Mineral (Impactite)

Galena

Lead Sulfide (PbS)

Muscovite Mica

KAl2(AlSi3O10)(OH)2

Chrysotile Asbestos

Chrysotile (Mg3Si2O5(OH)4)

Epidote

Epidote (Ca2(Al, Fe)3(SiO4)3(OH))

Muscovite Mica

KAl2(AlSi3O10)(OH)2

Muscovite Mica

Muscovite (KAl2(AlSi3O10)(OH)2)

Chalcopyrite

Copper Iron Sulfide (CuFeS2)

Quartz crystal cluster

Quartz (silicon dioxide, SiO₂), likely milky or druzy quartz

Rounded, weathered stone (likely basaltic or andesitic river cobble)

Fine-grained mafic to intermediate volcanic rock; exact identification requires examination of a fresh surface

Sandstone

Sandstone (composed primarily of sand-sized minerals or rock grains)

Small brown mineral or rock fragment

Undetermined; the image does not show enough detail for reliable identification

Botryoidal Hematite

Iron(III) oxide (Fe2O3)

Vanadinite

Lead Chlorovanadate, Pb5(VO4)3Cl

Pyrite in Quartz

Iron Sulfide (FeS2) in Silicon Dioxide (SiO2)

Microcline Feldspar (Amazonite or White Feldspar)

KAlSi3O8

Amygdaloidal Basalt with Quartz Veining

Basalt (Extrusive Igneous Rock) with Quartz (SiO2) veining

Gneiss

Gneiss (foliated metamorphic rock)

Granite with Mafic Xenolith

Intrusive Igneous Rock (Felsic to Intermediate)

Granite

Granite (Phaneritic Quartz-Feldspar Plutonic Rock)

Granite

Granite (Felsic Plutonic Rock)

Quartz Crystal

Silicon Dioxide (SiO2)

Blue apatite specimen

Apatite-group mineral, commonly fluorapatite (Ca₅(PO₄)₃F)

Basalt with an orange mineral vein

Fine-grained basalt, likely containing iron-stained calcite or zeolite; exact identification requires testing

Greenstone (likely chlorite- or actinolite-rich metabasalt)

Metamorphosed mafic volcanic rock; commonly greenschist-facies basalt, composed chiefly of chlorite, actinolite, epidote, and albite

Rounded dark-gray rock, likely diorite or andesite

Probable diorite (plagioclase and hornblende/pyroxene); identification is limited by the image

Exposed shoreline bedrock and sediment

Unidentified natural rock; the image does not show enough detail for a specific geological identification

Granite pebble

Granite; predominantly quartz, feldspar, and mica

Unidentified polished mineral specimen

Indeterminate; likely a pale feldspar or quartz-bearing material

Chalcedony (Botryoidal)

Silicon Dioxide (SiO2)

Quartz on Schist

Silicon Dioxide (SiO2) on Foliated Metamorphic Rock

Red garnet crystal cluster

Most likely almandine garnet, Fe₃Al₂(SiO₄)₃; exact species cannot be confirmed from the image alone.

Gneiss (specifically Banded Gneiss)

Gneiss

Fluorite (Rainbow, Purple-Blue Tumbled)

Calcium Fluoride (CaF2)

Quartz (Clear Quartz/Rock Crystal)

Silicon Dioxide (SiO2)

Granite

Phaneritic Felsic Igneous Rock

Basalt with Secondary Mineralization (Likely Zeolites or Calcite)

Aphanitic mafic volcanic rock with secondary mineral inclusions (e.g., CaAl2Si3O10·3H2O for Scolecite)

Rounded granite pebble

Granite, a quartz–feldspar–mica plutonic rock

Tumbled Mixed Gemstones and Rocks

Various mineral species including quartz (SiO2) and silicate minerals

Quartz with Mineral Inclusions

Silicon Dioxide (SiO2)

Green glass-like mineral specimen, likely fluorite

Fluorite (calcium fluoride, CaF₂), if natural; appearance may also indicate colored glass

Quartz Mineral

Silicon dioxide (SiO2)

Quartz Mineral

Silicon Dioxide (SiO2)