Mineralogical Specimen

Unakite (likely)

Epidote–pink feldspar–quartz rock; commonly termed unakite

Granite

Felsic intrusive igneous rock

Fossil ammonite

Ammonoidea; likely a chambered ammonite mold/cast

Likely serpentine-rich metamorphic rock

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

Basalt

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

Quartz-bearing weathered rock

Massive to drusy quartz (SiO₂), possibly in a feldspathic or carbonate host

Banded gneiss cobble

Gneiss, typically quartz–feldspar–mica assemblage

Rounded river pebble, likely quartz-rich sandstone or weathered quartzite

Indeterminate; probable quartz (SiO₂)-rich clastic rock

Sandstone (Quartzose Sandstone)

Arenite (primarily SiO2 with minor Fe2O3)

Probable weathered basalt or andesite

Fine-grained mafic to intermediate volcanic rock; commonly plagioclase ± pyroxene, amphibole, and iron oxides

Dalmatian jasper (often sold as Dalmatian stone)

Quartz-bearing leucocratic alkali-feldspar–aegirine/arfvedsonite porphyritic rock; commercial “jasper” designation

Granite

Granite (Felsic Plutonic Rock)

Quartzite

Metamorphosed Quartz Sandstone (SiO2)

Granite-like pegmatitic rock

Coarse-grained granite or granitic pegmatite; likely quartz–feldspar–mica aggregate

Weathered sandstone pebble

Quartz-rich sandstone, likely iron-oxide-stained (SiO₂-dominant)

Polished greenstone pebble (likely epidote-bearing stone)

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

Weathered green metamorphic rock, possibly serpentinite or greenstone

Likely serpentinite (serpentine-group minerals) or chlorite/epidote-rich greenschist; exact identification requires testing

Mica-rich pegmatitic granite

Granitic pegmatite, chiefly quartz, feldspar, and muscovite/biotite mica

Blue sodalite-bearing rock (likely sodalite rough)

Sodalite, Na₈(Al₆Si₆O₂₄)Cl₂, possibly in syenite or lapis-lazuli-like matrix

Serpentine-bearing metamorphic rock (likely chromite/vesuvianite-bearing serpentinite)

Serpentinite, chiefly serpentine-group minerals [(Mg,Fe)₃Si₂O₅(OH)₄], with dark accessory minerals

Serpentine-rich metamorphic rock

Serpentinite; chiefly antigorite/lizardite Mg₃Si₂O₅(OH)₄, possibly with talc, chlorite, magnetite, or carbonate

Dark mafic rock, likely basalt

Basalt; mainly plagioclase feldspar, pyroxene, and commonly olivine or magnetite

Weathered metal-rich igneous rock, likely basalt or komatiitic peridotite

Probable altered mafic–ultramafic rock containing pyroxene/amphibole, olivine, iron oxides, and possible metallic sulfides

Dark gray fine-grained stone, likely basalt

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

Serpentinized ultramafic rock with magnesite

Serpentinite, chiefly serpentine-group minerals (Mg₃Si₂O₅(OH)₄), with likely magnesite (MgCO₃) and minor chromite/magnetite

Quartzite

Quartzite (primarily SiO2)

Quartz-veined metamorphic rock, likely quartzite or schist

Quartz-rich metamorphic rock with a milky-quartz vein; exact host rock is indeterminate from the photo

Granite

Intrusive Igneous Rock

Polished dark green stone (likely serpentine or greenstone)

Serpentine-group mineral aggregate, commonly antigorite/lizardite; identification is uncertain from the image

Weathered, iron-stained feldspathic rock (probable granite or granitic pegmatite)

Quartz–feldspar granitoid; visible blue grains may be altered feldspar or accessory minerals

Likely weathered basalt pebble

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

Uncertain polymict breccia or altered volcanic rock

Likely hydrothermally altered volcanic breccia; exact mineral identification requires testing

Weathered iron-rich rock, possibly limonite-bearing sandstone

Limonite/goethite-bearing sandstone or ferruginous conglomeratic rock

Cat's Eye Moonstone (Feldspar)

Orthoclase (KAlSi3O8) with Albite (NaAlSi3O8) inclusions

Tumbled Slate or Basalt Pebble

Metamorphic fine-grained rock / Slate or Phyllite

Serpentinite with carbonate veins and weathering rind

Serpentinite; chiefly serpentine-group minerals (antigorite, lizardite, chrysotile), with calcite/magnesite and accessory magnetite

Gneiss (specifically a granitic gneiss cobble)

Gneiss (high-grade regional metamorphic rock)

Iron-rich breccia or weathered ironstone

Goethite–hematite-bearing ferruginous rock, possibly limonite

Likely weathered quartz-bearing rock

Indeterminate; possibly quartz-rich granite or granitic pegmatite

Likely basalt (possibly iron-rich volcanic rock)

Basalt; predominantly plagioclase feldspar, pyroxene, and commonly olivine or iron oxides

Weathered gray-green basaltic rock

Basalt, likely altered to low-grade greenschist/amphibolite facies

Greenstone / altered basalt (probable)

Chlorite–epidote–actinolite aggregate; commonly metabasalt (greenstone)