Mineral In A Matrix (Likely Quartz Or Feldspar)

Granite

Granite (Felsic Plutonic Rock)

Granite Cobble

Granitoid (composed mainly of Quartz, Feldspar, and Mica)

Weathered granitic rock fragment

Likely granite or granodiorite; quartz–feldspar–mica aggregate

Quartz-Mica Schist (with Muscovite)

Metamorphic Rock (Quartz, Muscovite, Feldspar)

Quartzite Pebble (with Iron Staining)

Quartzite (SiO2)

Tumbled milky quartz (probable)

Quartz, silicon dioxide (SiO₂)

Gneiss (specifically a Granitic Gneiss)

Gneiss (typically composed of Quartz, Feldspar, and Mica/Amphiboles)

Quartz-rich rock fragments, likely granite or gneiss

Granite/gneiss assemblage; chiefly quartz (SiO₂), feldspar, and mica

Fluorite-Gedrite in Quartz (Schist)

Fluorite (CaF2) with Gedrite in Quartz/Feldspar Matrix

Garnet-Mica Schist

Garnetiferous Porphyroblastic Schist

Quartz-veined Metamorphic Rock

Quartz Vein in Phyllite or Schist (SiO2 in Silicate Matrix)

Granite (likely weathered granite or granitic gneiss)

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

Granite Cobble

Granite (Phaneritic Igneous Rock)

Granitoid (Granite/Granodiorite)

Plutonic igneous rock (variable composition, primarily SiO2)

Weathered gneissic metamorphic rock

Gneiss, likely quartz–feldspar–mica gneiss

Quartz (Pinkish-Orange Variety)

Crystalline Silicon Dioxide (SiO2)

Dalmation Jasper

Aplite with Arfvedsonite inclusions (SiO2 with Na3(Mg,Fe2+)4AlSi8O22(OH)2)

Granite

Granite (dominated by Quartz, Alkali Feldspar, and Plagioclase)

Unakite-like granite

Altered granite, chiefly quartz, feldspar, mica, and red garnet

Rounded pink granite pebble

Granite, chiefly quartz, alkali feldspar, plagioclase, and minor biotite/hornblende

Granite Pebble

Granitoid (Quartz-Feldspar dominant rock)

Granite-like rock

Felsic intrusive igneous rock, likely granite or granodiorite

Blue-gray quartz-bearing metamorphic rock (likely gneiss or schist)

Quartz–feldspar–mica rock; exact identification requires testing

Black Tourmaline in Quartz and Feldspar Matrix

Schorl (NaFe3Al6(BO3)3Si6O18(OH)4) with Quartz and Feldspar

Uncertain fine-grained rock or mineral-bearing specimen

Indeterminate; possible quartz- or feldspar-bearing matrix with reflective grains

Amygdaloidal Basalt

Amygdaloidal Basalt (Mafic Volcanic Rock)

Graphic Granite

Pegmatitic Feldspar with Quartz intergrowths

Polished orbicular jasper / brecciated jasper

Jasper, microcrystalline quartz (SiO₂), with iron-oxide and clay-rich inclusions

Porphyritic Granite

Porphyritic Felsic Igneous Rock

River Cobble (likely Metasedimentary or Basalt)

Metamorphosed Siltstone or Altered Fine-grained Igneous Rock

Sedimentary rock with quartz veining

Laminated siltstone or mudstone with hydrothermal quartz veins

Weathered granitic rock

Granite or granodiorite, likely quartz–feldspar–mica aggregate

Granite (likely weathered granite or granitic gneiss)

Granite; mainly quartz (SiO₂), feldspar, and mica

Porphyritic Rhyolite (Red Rhyolite)

Rhyolite (Porphyry)

Biotite-bearing gneiss or schist

Quartz–feldspar–biotite metamorphic rock

Beryl (likely Pink/Morganite variety)

Beryllium aluminum silicate (Be3Al2Si6O18)

Granite

Felsic intrusive igneous rock

Weathered gray granitic rock

Granite, likely quartz–feldspar–mica aggregate

Weathered granitic rock

Granite, likely quartz–feldspar–mica aggregate

Tumbled granite pebble

Granite; primarily quartz, feldspar, and mica/amphibole

Granite

Granite (Mainly Quartz, Feldspar, and Mica)

Migmatite

Migmatite (Mixed metamorphic-igneous rock)