Sedimentary Rock (Altered)

Polished rhyolite (likely porphyritic rhyolite)

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

Unakite (likely tumbled)

Unakite; epidote–orthoclase–quartz aggregate

Red Jasper

Silicon Dioxide (Microcrystalline Quartz), SiO2

Weathered granite (feldspathic, iron-stained granite)

Granite; primarily quartz, potassium feldspar, plagioclase feldspar, and minor mica/amphibole. Exact identification is uncertain from a single photograph.

Weathered porphyritic volcanic rock, likely rhyolite or andesite

Porphyritic rhyolite–andesite; mainly quartz/feldspar phenocrysts in a fine iron-stained groundmass

Weathered basaltic rock (probable vesicular basalt)

Basalt; primarily plagioclase feldspar, pyroxene, and commonly olivine, with iron-oxide alteration

Green schist (probable)

Chlorite–mica schist; exact mineralogy cannot be confirmed from the photograph

Likely serpentine or serpentinite

Serpentine-group minerals, chiefly antigorite, lizardite, or chrysotile; approximate formula Mg3Si2O5(OH)4

Lapis Lazuli (polished cabochon)

Lazurite-rich metamorphic rock (approx. Na6Ca2Al6Si6O24(SO4,S,Cl)2)

Greenstone pebble (likely altered basalt)

Chlorite–actinolite–epidote altered basalt; precise identification requires testing

Pink-and-white quartz-rich pebble

Quartz (SiO₂), likely massive quartz with iron-oxide staining and possible feldspar inclusions

Epidote

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

River Pebble (Granite/Gneiss)

Granitic Pebble (Quartz, Feldspar, Mica composition)

Polished tiger iron

Tiger iron, a banded aggregate of tiger’s-eye (quartz), red jasper, and hematite/magnetite

Lapis Lazuli

Lazurite-rich metamorphic rock ((Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)

Weathered granite-like rock

Granite or granodiorite; quartz–feldspar–mica aggregate

Tumbled amber

Fossilized plant resin; chiefly polymerized diterpenoid resin (succinite)

Jasper and Epidote Breccia

Silicified Brecciated Rock with Epidote

Banded Iron Formation (BIF)

Banded Iron Formation (SiO2 + Fe2O3)

Gold-bearing quartz vein ore

Native gold (Au) in quartz with iron-oxide alteration; likely limonite/goethite and possibly sulfides

Orange chalcedony / carnelian with drusy quartz

Microcrystalline quartz, SiO₂ (chalcedony; iron-colored variety often called carnelian), with possible calcite or quartz matrix

Polished greenstone pebble (likely epidote-bearing stone)

Epidote–chlorite amphibolite or altered basalt; composition likely epidote, chlorite, amphibole/pyroxene, and iron oxides

Serpentinite (serpentinized ultramafic rock)

Serpentinite; chiefly serpentine-group minerals (Mg₃Si₂O₅(OH)₄), with magnetite, brucite, and residual olivine/pyroxene

Weathered quartz-rich rock, possibly granite or quartzite

Indeterminate; likely quartz–feldspar aggregate, possibly altered granite

Basalt in a vesicular volcanic host rock

Basalt, likely with secondary zeolite or calcite infill

Tumbled epidote-bearing rock (likely epidote–quartz–feldspar aggregate)

Epidote-rich metamorphic rock; minerals likely epidote (Ca₂(Al,Fe)₃Si₃O₁₂(OH), quartz, feldspar, and dark amphibole/biotite)

Unakite (likely epidote–feldspar rock)

Epidote–K-feldspar–quartz aggregate; commonly approximated as pink orthoclase/microcline + green epidote + quartz

Unakite Jasper / Unakite

Altered Granite (containing Epidote, Orthoclase Feldspar, and Quartz)

Tumbled greenstone, likely serpentine or altered jade-like rock

Serpentinite (predominantly serpentine-group minerals; Mg₃Si₂O₅(OH)₄), possibly nephrite jade if notably tough and dense

Tumbled green stone, likely serpentine

Serpentine-group minerals, chiefly antigorite or lizardite; approximate composition Mg₃Si₂O₅(OH)₄

Greenstone / Chert

Cryptocrystalline Quartz (SiO2) or Altered Basalt

Likely weathered basalt with iron-oxide alteration

Basalt (fine-grained mafic volcanic rock), chiefly plagioclase and pyroxene with altered iron-bearing minerals

Greenstone / altered basalt (probable)

Chlorite–actinolite–epidote rock; commonly derived from basalt or gabbro

Mixed mineral specimens, prominently chalcopyrite and amethyst

Chalcopyrite (CuFeS₂) with secondary copper minerals; amethyst, purple quartz (SiO₂)

Weathered granitic rock

Granite or granodiorite, likely quartz–feldspar–mica aggregate

Weathered gray-green metamorphic rock, likely serpentinite or altered basalt

Serpentinite, chiefly serpentine-group minerals (antigorite/lizardite); identification is provisional from the photograph

Serpentine (rough serpentine-rich rock)

Serpentine-group minerals, chiefly antigorite and/or lizardite; composition broadly Mg₃Si₂O₅(OH)₄

Gneiss (likely garnet-bearing or migmatitic gneiss)

Felsic banded gneiss; chiefly quartz, feldspar, mica, and possibly garnet

Jasper Pebble

Microcrystalline Quartz (Chalcedony), SiO2

Fuchsite

Chromium-rich Muscovite (K(Al,Cr)2(AlSi3O10)(OH)2)

Polymictic breccia, possibly volcanic breccia

Polymictic clastic breccia; likely a matrix-supported breccia containing lithic fragments, quartz, feldspar, and dark mafic minerals

Unidentified gray-green crystalline rock

Possibly chlorite schist or altered amphibolite; image alone is insufficient for definitive identification