Sedimentary Rock (Altered)

Rounded banded metamorphic cobble, likely greenstone or serpentinite

Probable greenschist-facies metavolcanic rock (chlorite–actinolite schist) or serpentinized ultramafic rock

Likely turquoise (polished cabochon)

Turquoise, hydrated copper–aluminum phosphate: CuAl₆(PO₄)₄(OH)₈·4H₂O

Quartz-veined dark metamorphic rock, likely marble or serpentinite

Calcite- or magnesite-veined serpentinite/marble; exact identification requires testing

Weathered basaltic rock

Basalt, likely altered basalt (plagioclase–pyroxene ± olivine; possible iron-oxide staining)

Milky Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Unakite (likely, rough specimen)

Epidote–feldspar–quartz rock; commonly approximated as pink orthoclase + green epidote + quartz

Rounded river pebble, likely basaltic or andesitic volcanic rock

Fine-grained mafic to intermediate volcanic rock; likely basalt/andesite, but exact identification requires testing

Rounded greenish stone, possibly serpentinite or greenstone

Likely serpentinite (hydrated ultramafic rock; chiefly serpentine-group minerals), but the photograph is insufficient for confident species identification

Garnet Gneiss

Garnetiferous quartzo-feldspathic gneiss

Likely weathered sulfide ore, possibly galena-bearing rock

Uncertain from the photograph; dark metallic portion may be galena (PbS) in a rusty iron-oxide matrix

Weathered basaltic rock

Basalt, likely vesicular or altered basalt

Weathered green-gray stone, likely serpentinite or chlorite-rich metamorphic rock

Probable serpentinite (antigorite–lizardite), possibly chlorite schist or altered basalt

Weathered iron-rich rock, possibly ironstone or altered basalt

Indeterminate; likely ferruginous basalt/ironstone containing hematite-goethite and silicate minerals

Polished amethyst-bearing rock, likely amethyst in matrix

Amethyst (purple quartz, SiO₂), with an unidentified dark host-rock matrix

Milky quartz vein rock

Quartz, silicon dioxide (SiO₂), likely with iron-oxide staining and minor mica or sulfide minerals

Tumbled reddish-brown volcanic rock, likely basalt or andesite

Fine-grained mafic to intermediate igneous rock; commonly plagioclase with pyroxene and/or olivine, possibly iron oxides

Polished basalt pebble

Vesicular to amygdaloidal basalt, composed mainly of plagioclase, pyroxene, and iron-rich oxides

Iron-rich jasper (likely brecciated jasper)

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

Quartz-rich granite or granitic gneiss

Granite; primarily quartz (SiO₂), feldspar, and minor mica

Epidote

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

Quartz-rich stone, possibly aventurine quartz or quartzite

Quartz (SiO₂), likely massive or microcrystalline; exact identification requires testing

Polished jasper

Microcrystalline quartz (chalcedony), SiO₂, with iron-oxide inclusions

Polished brown river pebble

Likely quartzite or weathered metabasalt; exact identification requires hardness and streak tests

Green-and-gold apatite-bearing rock, possibly epidote skarn

Apatite-group mineral, commonly fluorapatite (Ca₅(PO₄)₃F), with probable epidote and quartz; exact identification requires testing

Tumbled lapis lazuli

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

Orbicular jasper (ocean jasper)

Microcrystalline quartz (SiO₂), chiefly chalcedony with feldspar, zeolites, and iron-oxide inclusions

Weathered copper-bearing porphyritic rock (probable andesite or altered volcanic rock)

Likely propylitically altered andesite/latite; green color may reflect chlorite, epidote, or chrysocolla/malachite staining

Unidentified rounded rock, likely granite or granitic gneiss

Quartz–feldspar–mica rock; exact identification is uncertain from the image

Quartzite with Mica Matrix

Metamorphic Quartz-Mica Schist/Quartzite

Unidentified weathered rock fragments

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

Black-veined pebble, likely basalt in a weathered host rock

Probable basaltic dike or vein in altered volcanic rock; exact identification requires testing

Polished serpentine (likely greenstone)

Serpentine-group minerals, chiefly antigorite/lizardite: Mg₃Si₂O₅(OH)₄

Quartz-rich veined rock, likely milky quartz with feldspar or calcite

Quartz (SiO₂), possibly in a quartz–feldspar or quartz–calcite vein

Unakite

Epidotized Granite

Unidentified weathered mineral/rock fragment

Indeterminate; likely a weathered iron-rich silicate or sulfide-bearing specimen

Pale blue-green altered volcanic rock, likely basalt

Altered basalt (fine-grained plagioclase–pyroxene rock with secondary zeolite/chlorite minerals)

Iron-stained milky quartz vein

Quartz (SiO₂), with iron-oxide/hydroxide staining and minor dark inclusions

Lapis Lazuli

Lazurite-rich metamorphic rock (complex silicate)

Weathered vesicular basalt (likely amygdaloidal basalt)

Basalt, composed mainly of plagioclase feldspar, pyroxene, and altered olivine; cavities may contain secondary zeolite, calcite, or silica

Jasper

Silicon dioxide (SiO2) microcrystalline quartz

Milky quartz vein in altered host rock

Quartz (SiO₂), likely with feldspar, mica, and iron-oxide alteration

Pale green rough mineral specimen, likely serpentine or calcite

Probable serpentine-group mineral, Mg₃Si₂O₅(OH)₄; possibly pale-green calcite, CaCO₃