Metamorphic (Man Made)

Biotite-rich schist

Mica schist; chiefly quartz, biotite mica, feldspar, and accessory sulfides/iron oxides

Graphitic schist (probable)

Graphite-bearing mica schist; chiefly quartz, mica, and graphite

Likely mica-rich schist (possibly phyllite)

Muscovite–biotite schist; exact identification requires examination of a fresh surface

Milky quartz-bearing rock, possibly quartzite

Quartz (SiO₂), likely in a quartzite or quartz-rich vein

Quartz Crystal Cluster / Quartzite

Silicon Dioxide (SiO2)

Banded gneiss pebble

Gneiss, commonly quartz–feldspar–mica gneiss

Greenstone (likely serpentinite)

Serpentinite, chiefly serpentine-group minerals (Mg₃Si₂O₅(OH)₄), possibly with chlorite or magnetite

Plagioclase Feldspar (specifically Albite/Oligoclase)

(Na,Ca)(Si,Al)4O8

Likely raw garnet fragment

Garnet-group silicate, commonly almandine (Fe₃Al₂Si₃O₁₂)

Dyed Blue Agate Slice

Silicon Dioxide (SiO2)

Milky quartz (likely quartzite or massive quartz)

Quartz, silicon dioxide (SiO₂)

Small polished gemstone chips, likely mixed quartz varieties

Quartz (SiO₂), possibly including smoky quartz and other varieties; exact identification is uncertain from the image

Quartz

Quartz (SiO₂)

Quartz crystal cluster

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

Black-and-white banded pebble (likely gneiss or migmatite)

Undetermined banded metamorphic rock; mineral composition cannot be confirmed from the image

Pyrite (“fool’s gold”) specimens

Pyrite, iron disulfide (FeS₂)

Muscovite Mica

Muscovite (KAl2(AlSi3O10)(OH)2)

Red Jasper (Quartzite)

Silicon Dioxide (SiO2) with iron oxide inclusions

Serpentinite (probable)

Serpentinite; chiefly serpentine-group minerals (antigorite/lizardite/chrysotile), commonly with magnetite and minor olivine/pyroxene

Small brown mineral fragment

Unidentified; the image lacks enough detail for a reliable species-level identification

Milky quartz

Quartz (silicon dioxide, SiO₂)

Tumbled Clear Quartz

Silicon Dioxide (SiO2)

Likely gray slate or fine-grained argillite fragment

Slate, a low-grade metamorphic rock derived from shale; exact identification is uncertain from the image

Yellow Jade

Jadeite or Nephrite (NaAlSi2O6 or Ca2(Mg,Fe)5Si8O22(OH)2)

Brecciated jasper/quartz-rich polymictic rock

Silicified breccia, chiefly microcrystalline quartz (SiO₂) with iron-oxide and sulfide staining

Calcite

Calcite (CaCO3)

Polished rhodonite

Rhodonite, manganese inosilicate (MnSiO₃), commonly mixed with quartz and manganese oxides

Mixed mineral and rock specimen collection

Mixed assemblage, visibly including quartz, chalcedony/agate, feldspar, mica, dark mafic rocks, and possibly calcite or gypsum

Quartz

Silicon Dioxide (SiO2)

Quartz Crystal

Silicon Dioxide (SiO2)

White Quartz

Silicon Dioxide (SiO2)

Marble

Metamorphosed Limestone (principally CaCO3)

Emerald (Rough)

Beryl (Be3Al2Si6O18 with Chromium/Vanadium impurities)

Unidentified dark, foliated metamorphic rock

Likely biotite schist or hornblende-bearing gneiss; exact identification requires testing

Quartz-veined dark metamorphic rock

Likely quartz-mica schist or foliated basalt with a quartz vein

Banded Calcite or Travertine

Calcium Carbonate (CaCO3)

Milky quartz fragment

Quartz (SiO₂)

Citrine

Silicon Dioxide (SiO2)

Tumbled pink quartzite or quartz-rich stone

Quartzite, predominantly crystalline SiO₂

Polished dark river pebble, likely serpentinite or altered ultramafic rock

Serpentinite (predominantly serpentine-group minerals; identification is provisional)

Quartz Crystal

Silicon Dioxide (SiO2)

Greenstone

Metabasalt / Greenschist facies rock