Mineral In A Matrix (Likely Quartz Or Feldspar)

Banded sandstone pebble

Quartz-rich sandstone, likely with a contrasting siltstone or fine-grained sandstone band

Orbicular/porphyritic granite or granitic pegmatite

Quartz–feldspar–mica granitic rock, possibly orbicular granite

Sandstone

Arenite (SiO2 based with mineral cement)

Tumbled granite or granitic pebble

Granite; primarily quartz, feldspar, and mica (exact variety uncertain from the image)

Granite pebble

Coarse-grained felsic intrusive igneous rock; mainly quartz, alkali feldspar, plagioclase, and minor biotite or amphibole

Granite

Phaneritic Igneous Rock (Granite)

Quartz Vein in Host Rock

Silicon Dioxide (SiO2) in matrix

Basalt with Epidote (Porphyry)

Basalt (with inclusions of Epidote/Feldspar)

Diorite Porphyry (Polished Pebble)

Diorite

Vuggy Quartz on Matrix

Silicon Dioxide (SiO2)

Granite

Intrusive Phaneritic Felsic Igneous Rock

Vesicular Basalt with Calcification

Vesicular Basalt (Aphanitic extrusive igneous rock)

Gold in Quartz Matrix

Native Gold (Au) with Quartz (SiO2) and Slate/Shale

Mixed Rock and Mineral Collection

Mixed Assemblage (includes Quartz, Jasper, Feldspar, and Turquoise-colored stones)

Graphic Granite (Runic Granite)

Pegmatite (Graphic Granite variety)

Milky quartz-bearing rock, likely quartzite or silicified limestone

Quartz (SiO₂), possibly in a quartzite or chalcedony-rich matrix

Dalmatian Stone

Dalmatian Stone (a variety of aplite)

Weathered quartz-rich rock fragments

Probable granite or granitic gneiss; quartz (SiO₂), feldspar, and mica

Quartz with Mafic Inclusions

Silicon Dioxide (SiO2) with host igneous matrix

Granodiorite Core

Granodiorite

Conglomeratic sandstone or breccia

Lithic arkose / polymictic conglomeratic sandstone

Sandstone

Arenite (SiO2 primarily)

Purple fluorite-bearing matrix specimen

Fluorite (calcium fluoride, CaF₂), likely with quartz and host-rock minerals

Gneiss (specifically Granitic Gneiss)

Gneiss

Wishing Stone (Basalt/Metabasalt with Quartz-Feldspar Vein)

Veined Metabasalt / Veined Greywacke

Quartz Pebble with Muscovite Mica

Quartzite / Quartz-Mica Schist pebble (SiO2 with KAl2(AlSi3O10)(OH)2)

Amazonite

Microcline (KAlSi3O8) with trace lead (Pb)

Quartz in Basalt (Xenocryst)

Silicon Dioxide (SiO2) in Mafic Igneous Volcanic Rock

Milky quartz

Quartz (silicon dioxide, SiO₂)

Quartz pebble with host matrix

Silicon Dioxide (SiO2)

Vein-bearing metamorphic rock, likely gneiss or schist

Banded silicate rock; likely quartz–feldspar–mica gneiss with a quartz vein

Weathered granitic rock (likely biotite granite)

Granite; chiefly quartz, potassium feldspar, plagioclase, and biotite mica

Pink granite (likely weathered granite or granitic gneiss)

Granite; chiefly quartz (SiO₂), feldspar, and biotite/amphibole

Granite or granitic rock fragment

Coarse-grained felsic intrusive rock, chiefly quartz, feldspar, and mica/amphibole

Weathered pegmatitic granite (likely biotite granite)

Coarse-grained granite dominated by quartz, potassium feldspar, plagioclase, and biotite; exact identification requires testing

Granite Pebble

Granite (Felsic Plutonic Rock)

Quartz-bearing metamorphic rock, likely garnet-mica schist

Quartz–mica schist with probable garnet and iron-oxide minerals

Pink feldspar-bearing granite or pegmatite fragment

Mostly potassium feldspar (orthoclase/microcline), quartz, and minor mica; exact identification requires testing

Weathered granite or granitic gneiss slab

Granitic rock, chiefly quartz, feldspar, and mica; exact identification is uncertain from the photograph

Likely gneissic amphibolite or banded metamorphic rock

Hornblende–biotite gneiss/amphibolite; exact identification requires a fresh surface or thin section

Weathered granitic rock fragment

Likely granite or granodiorite, composed mainly of quartz, feldspar, and mica

Granite pebble

Granite, chiefly quartz, feldspar, and mica