Metamorphic (Altered Igneous Rock)

Iron-stained quartz-rich metamorphic rock (probable quartzite or hydrothermal vein rock)

Quartz-dominant rock; chiefly SiO₂, with iron oxides/hydroxides and minor sulfide minerals

Weathered granite pebble

Granite, predominantly quartz–feldspar–mica aggregate

Dark metamorphic rock, likely slate or phyllite

Fine-grained foliated metamorphic rock; commonly dominated by quartz, mica, and chlorite

Basalt with pale mineral veins/coating

Likely vesicular or altered basalt, with calcite or zeolite minerals

Weathered sandstone or iron-stained sedimentary rock

Quartz-rich sandstone, likely limonitic/goethitic cement

Granite (likely biotite granite or granodiorite)

Coarse-grained granitoid composed mainly of quartz, feldspar, and dark biotite/amphibole

Likely dark green jasper or serpentinite pebble

Undetermined fine-grained rock; possible serpentine-group mineral (approx. Mg₃Si₂O₅(OH)₄) or jasper (microcrystalline SiO₂)

Weathered quartz-rich rock, possibly silicified volcanic rock

Likely quartz (SiO₂) with iron-oxide staining; host may be altered rhyolite or andesite

Weathered greenstone pebble (probable serpentinite or altered basalt)

Serpentinite-group rock, commonly dominated by antigorite/lizardite; identification is uncertain from the photograph

Small polished green stone, possibly serpentine or greenstone

Likely serpentine-rich rock; exact identification is limited by the blurred image

Weathered granitic rock

Granite, likely quartz–feldspar–biotite granitoid

Weathered porphyritic volcanic rock (likely andesite or basalt)

Porphyritic andesite/basalt; typically plagioclase feldspar ± pyroxene, olivine, and iron oxides

Weathered iron-rich rock fragment

Indeterminate; likely basaltic or mafic rock with iron-oxide staining

Gold-bearing quartz vein rock (likely pyrite-rich quartzite)

Quartz (SiO₂) with iron sulfides, chiefly pyrite (FeS₂), possibly chalcopyrite (CuFeS₂); gold cannot be confirmed visually

Weathered river cobble, likely basaltic or andesitic volcanic rock

Fine-grained mafic to intermediate igneous rock; exact identification requires testing

Green serpentine (likely serpentinite)

Serpentine-group minerals, commonly antigorite, lizardite, and/or chrysotile; rock name: serpentinite

Rounded porphyritic volcanic rock, likely andesite

Porphyritic andesite; chiefly plagioclase feldspar, pyroxene and/or hornblende in a fine volcanic groundmass

Polished orbicular granite (likely larvikite or orbicular diorite)

Quartz/feldspar-bearing granitoid with dark amphibole–biotite minerals; exact variety requires testing

Fine-grained gray rock, likely andesite or basalt

Aphanitic volcanic rock; probable basaltic-andesite (plagioclase ± pyroxene, minor iron oxides)

Lapis Lazuli

Lapis Lazuli (Complex rock consisting primarily of Lazurite (Na,Ca)8(AlSiO4)6(S,SO4,Cl)1-2)

Pink granite or granitic gneiss

Granite; mainly quartz, alkali feldspar, plagioclase, and minor mica

Red vesicular volcanic rock, likely scoria

Scoria (vesicular basalt/andesite), composition mainly plagioclase, pyroxene, iron oxides, and volcanic glass

Weathered basalt (likely)

Basalt; fine-grained mafic volcanic rock, chiefly plagioclase and pyroxene with possible olivine

Red-brown iron-rich rock, likely hematite-bearing basalt or ironstone

Provisional identification: hematite (Fe₂O₃)-stained mafic rock; possibly weathered basalt or ferruginous chert

Iron-stained quartz-rich rock, likely pegmatite or quartz vein fragment

Quartz (SiO₂) with feldspar, mica, and iron-oxide/hydroxide staining; possibly weathered granite pegmatite

Gray volcanic rock, likely basalt

Basalt; primarily plagioclase feldspar, pyroxene, and minor olivine/iron oxides

Weathered basalt (possible volcanic bomb)

Basalt; primarily plagioclase feldspar, clinopyroxene, and iron-titanium oxides

Weathered porphyritic volcanic rock, possibly rhyolite or andesite

Altered porphyritic rhyolite–andesite; likely quartz/feldspar phenocrysts in a fine volcanic groundmass

Weathered iron-rich rock, possibly limonite-bearing basalt or laterite

Indeterminate; likely Fe-oxide/hydroxide–altered mafic rock, dominated by limonite/goethite with silicate minerals

Rounded green-gray stone, likely serpentinite or altered basalt

Serpentinite (antigorite/lizardite-rich), possibly serpentinized ultramafic rock

Tumbled jasper, likely red/brown jasper

Microcrystalline quartz (chalcedony), SiO₂, colored by iron oxides

Volcanic breccia or conglomeratic volcanic rock

Lithic volcanic breccia; possibly andesitic–basaltic matrix with feldspar-rich clasts

Weathered basalt (possibly iron-stained volcanic rock)

Basalt; predominantly plagioclase, pyroxene, and possibly olivine, with iron-oxide staining

Quartz-bearing greenstone (probable epidote–quartz rock)

Epidote–quartz schist/greenstone; chiefly quartz (SiO₂) and epidote [Ca₂(Al,Fe)₃(SiO₄)₃(OH)], with possible chlorite and feldspar

Weathered quartz-rich rock, likely granite or pegmatite

Granitic pegmatite; chiefly quartz (SiO₂), feldspar, and mica, with possible iron-oxide staining

Porphyritic volcanic rock, likely andesite or basalt with weathered feldspar phenocrysts

Porphyritic andesite–basalt; chiefly plagioclase feldspar and pyroxene, with possible olivine or iron oxides

Weathered iron-rich rock, possibly limonite-bearing breccia or altered basalt

Indeterminate; likely Fe-oxide/hydroxide–stained silicate rock, dominated by limonite/goethite with possible quartz or feldspar

Granite pebble

Granite; chiefly quartz, potassium feldspar, plagioclase, and minor biotite/hornblende

Unakite (likely)

Epidote–orthoclase–quartz rock; composition approximately epidote Ca₂(Al,Fe³⁺)₃(SiO₄)₃(OH) plus K-feldspar and quartz

Smoky Quartz

Silicon Dioxide (SiO2)

Serpentinite

Serpentinite, composed chiefly of serpentine-group minerals (e.g., antigorite, lizardite, chrysotile)

Polished Rhodonite Obelisk

Rhodonite (Manganese Iron Magnesium Calcium Silicate) - (Mn,Fe,Mg,Ca)SiO3