Metamorphic (Altered Igneous Rock)

Phyllite (possibly low-grade greenish slate)

Foliated metamorphic rock composed mainly of very fine-grained quartz, mica, and chlorite; approximate composition varies and has no single fixed chemical formula

Weathered greenish rock fragment

Indeterminate; possibly epidote- or chlorite-bearing altered silicate rock

Unidentified weathered rock fragments

Likely mixed quartz- and feldspar-bearing silicate material; exact identification requires testing

Tumbled lapis lazuli

Lapis lazuli; predominantly lazurite, (Na,Ca)₈(AlSiO₄)₆(S,SO)₄, with calcite and pyrite

Weathered basaltic rock (likely basalt)

Basalt; fine-grained mafic volcanic rock composed mainly of plagioclase, pyroxene, and commonly olivine

Citrine (Heat-treated or Natural Quartz)

Silicon Dioxide (SiO2)

Weathered brown mineralized rock

Likely iron-stained quartzite or quartz-rich metamorphic rock; exact identification requires testing

Unakite

Altered Granite (Epidote-bearing Granitic Rock)

Unakite

Epidote–pink feldspar–quartz rock

Quartz-bearing metamorphic rock, possibly epidote/quartzite

Quartz-rich rock with possible epidote and feldspar; exact identification requires testing

Weathered basaltic cobble

Altered basalt, predominantly plagioclase and pyroxene

Tumbled greenish jasper

Jasper, microcrystalline quartz (SiO₂) with iron-bearing and clay-mineral impurities

Polished serpentine (likely green serpentinite)

Serpentinite; chiefly serpentine-group minerals, Mg₃Si₂O₅(OH)₄, with magnetite and possible chromite or carbonate inclusions

Peridotite (Dunite/Lherzolite)

Ultramafic Peridotite

Tumbled iron-rich stone, possibly jasper or weathered basalt

Indeterminate; likely iron-stained microcrystalline quartz (jasper) or altered basalt

Quartzite

Metamorphic Quartzite (SiO2)

Unakite

Altered Granite (Plagioclase-Epidote-Quartz Rock)

Serpentinite (serpentinized ultramafic rock)

Serpentine-group minerals, chiefly lizardite and antigorite; commonly derived from peridotite

Greenstone with Epidote or Quartz Vein

Epidiorite or Metabasalt (composed largely of Chlorite, Epidote, and Amphibole)

Unakite-like epidote–feldspar rock

Epidote + K-feldspar/plagioclase ± quartz; compositionally similar to unakite

Epidosite (Unakite-related)

Epidosite (predominantly Epidote, Ca2(Al2,Fe3+)(SiO4)3(OH))

Epidosite

Epidosite (consisting primarily of Epidote Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH) and Quartz SiO2)

Likely raw epidote or altered amphibole crystal

Epidote, Ca₂(Al,Fe³⁺)₃(SiO₄)₃(OH); identification is tentative from the image

Uncertain polymict breccia or altered volcanic rock

Likely hydrothermally altered volcanic breccia; exact mineral identification requires testing

Smoky Quartz

Silicon Dioxide (SiO2)

Jasper and Epidote in Quartzite

Metamorphic rock containing microcrystalline quartz, epidote, and jasper

Weathered mica schist (tentative)

Mica schist, likely muscovite–biotite schist with quartz and feldspar

Polished granite pebble

Granite; chiefly quartz, feldspar, and mica/amphibole

Green Granite / Verd Antique

Serpentinite / Metasomatized Peridotite

Porphyritic basalt or weathered volcanic rock

Basalt, likely plagioclase–pyroxene rock with possible olivine; exact identification requires testing

Polished rhyolite (likely porphyritic rhyolite)

Rhyolite, composed chiefly of quartz and alkali feldspar with minor plagioclase, biotite, and iron oxides

Iron-rich jasper (likely brecciated jasper)

Microcrystalline quartz/chalcedony (SiO₂) colored by hematite/goethite; possibly iron formation

Epidote

Epidote; Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)

Tumbled tiger’s-eye-rich quartzite

Quartzite, composed mainly of microcrystalline quartz (SiO₂) with fibrous crocidolite pseudomorphs and iron oxides

Banded Rock (likely Quartz-rich)

Uncertain, likely a Metamorphic Rock (e.g., Gneiss or Schist) with prominent Quartz and other minerals

Sodalite

Na8(Al6Si6O24)Cl2

Weathered granitic rock

Granite or granodiorite, likely quartz–feldspar–mica aggregate

Citrine

Silicon Dioxide (SiO₂)

Citrine

Silicon Dioxide (SiO2)

Weathered granitic rock

Granite or granodiorite; primarily quartz (SiO₂), feldspar, and mica

Weathered granite or granitic gneiss

Quartz–feldspar–mica rock; likely granitoid, possibly weakly gneissic

Blue-gray quartz-bearing rock, likely dumortierite quartz or silicified metamorphic rock

Quartz (SiO₂) with probable dumortierite and iron-oxide inclusions