Mineral In A Matrix (Likely Quartz Or Feldspar)

Milky quartz (likely quartz crystal)

Quartz, silicon dioxide (SiO₂)

Weathered conglomerate pebble

Polymict conglomerate, likely ferruginous and quartz-rich

Tumbled pink quartz (likely rose quartz)

Quartz, silicon dioxide (SiO₂), pink variety commonly called rose quartz

Aquamarine-bearing quartz specimen

Beryl (Be₃Al₂Si₆O₁₈), likely aquamarine, on quartz (SiO₂)

Polished orbicular granite (likely orbicular diorite)

Orbicular granitoid; chiefly quartz, feldspar, and dark amphibole/biotite

Black-and-white granite (likely granodiorite)

Granite: quartz, feldspar, and dark mica/amphibole; exact identification is uncertain from the photo

Ocellar Rhyolite

Rhyolite (featuring orbicular/ocellar quartz and feldspar textures)

Ocean Jasper (Orbicular Jasper)

Spherulitic Chalcedony/Rhyolite (SiO2)

Quartz-rich geode or drusy quartz specimen

Quartz, silicon dioxide (SiO₂), likely coating a carbonate or volcanic-rock cavity

Quartz-rich pegmatite, possibly rose quartz

Quartz (SiO₂) in a coarse granitic pegmatite matrix, with iron-oxide staining

Garnet-bearing metamorphic rock

Likely garnet schist or garnet amphibolite; garnet is commonly almandine, Fe₃Al₂(SiO₄)₃

Quartz-rich rock fragment, likely milky quartz

Quartz (silicon dioxide, SiO₂), possibly an iron-stained quartz vein fragment

Quartz vein rock with iron-stained matrix

Quartz (SiO₂), likely with limonite/goethite and minor feldspar or mica

Quartz-rich rock, likely milky quartz or quartzite

Quartz (SiO₂), possibly in a quartzite or hydrothermal vein matrix

Orbicular rhyolite (likely)

Silica-rich volcanic rock, chiefly quartz and feldspar with orbicular aggregates of feldspar, quartz, and mafic minerals

Tumbled orbicular granite

Granite, commonly biotite–quartz–feldspar granite with orbicular or mafic enclaves

Black tourmaline (schorl) on quartz matrix

Schorl, NaFe3Al6(BO3)3Si6O18(OH)4, commonly associated with quartz (SiO2)

Pink druzy quartz (possibly quartz-bearing calcite)

Quartz, SiO₂; the pale pink coloration may reflect iron impurities or included feldspar. Exact identification is uncertain from the image alone.

Red Granite

Phaneritic Felsic Igneous Rock (Quartz, Alkali Feldspar, Plagioclase)

Granite-like rock fragment

Likely leucocratic granite or granitic pegmatite; exact identification requires a fresh surface and mineral testing.

Rhyolite Porphyry

Rhyolite (High-silica volcanic rock)

Quartz-rich granite or granitic pegmatite fragment

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

Basalt Porphyry

Porphyritic Basalt

Weathered granite or granitic gneiss boulder

Granite–gneiss; chiefly quartz, feldspar, and mica

Granite (small weathered fragment)

Granite, chiefly quartz, feldspar, and mica

Tumbled-looking granite pebble

Granite, chiefly quartz–feldspar with biotite/amphibole

Unidentified pale pink rough mineral specimen

Possibly rose quartz or feldspar; identification is uncertain from the photograph

Weathered quartz-bearing rock

Likely quartz-veined schist or gneiss; exact identification is uncertain from the image

Vesicular basalt (likely amygdaloidal basalt)

Basalt, a mafic volcanic rock composed mainly of plagioclase feldspar, clinopyroxene, and commonly olivine; vesicles are partly mineral-filled amygdules.

Sandstone (Banded)

Arenite

Gabbro or Diorite with Quartz/Epidote Vein

Intrusive Igneous Rock (Plutonic)

Orbicular jasper (likely ocean jasper)

Silica-rich microcrystalline quartz/chalcedony with iron-oxide and feldspar inclusions; commonly marketed as Ocean Jasper

Porphyritic basalt (likely amygdaloidal basalt)

Basalt, a mafic volcanic rock; composition typically plagioclase + pyroxene, with possible olivine and vesicle-filling minerals

Weathered foliated metamorphic rock, likely schist or gneiss

Micaceous schist/gneiss; composition likely quartz, feldspar, mica, and altered mafic minerals

Unidentified rough mineral fragments

Likely quartz- or feldspar-bearing rock; exact identification requires testing

Reddish-brown crystalline rock, possibly weathered granite or garnet-bearing schist

Indeterminate; likely quartz–feldspar–mica rock with iron oxides, potentially garnet-bearing

Garnet-bearing metamorphic rock, likely schist or gneiss

Biotite–garnet schist/gneiss; dark minerals likely biotite and graphite or amphibole, with quartz and feldspar

Small rounded pale stone

Indeterminate; likely quartz-rich pebble, possibly quartz or light-colored feldspar

Polished ocean jasper or orbicular rhyolite

Silicified, spherulitic rhyolite; chiefly quartz, feldspar, and chalcedony

Conglomeratic sandstone or breccia specimen

Quartz-rich clastic sedimentary rock; likely sandstone with pebble-sized quartz, feldspar, and lithic clasts

Porphyritic volcanic rock (likely rhyolite or andesite)

Porphyritic rhyolite–andesite; fine volcanic groundmass with feldspar and mafic phenocrysts

Porphyritic volcanic rock (likely andesite porphyry)

Porphyritic andesite; composition cannot be confirmed from the photograph