Mineral In A Matrix (Likely Quartz Or Feldspar)

Porphyritic Basalt or Andesite

Porphyritic Basalt/Andesite

Granite (likely Kashmir/ivory-type granite)

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

Quartz Veined Rock (Likely Graywacke or Quartzite)

Silicon Dioxide (SiO2) veins in Metasedimentary matrix

Quartzite and Milky Quartz River Pebbles

Silicon Dioxide (SiO2)

Weathered feldspathic quartzite or granitic rock fragment

Quartz-rich silicate rock; exact identification requires thin-section or chemical testing

Weathered granite or granitic gneiss fragment

Quartz–feldspar–mica granite; possibly foliated granitic gneiss

Granite

Granite

Quartz pebble in concrete

Quartz (SiO₂), embedded in Portland-cement concrete

Graphic Granite

Graphic Granite (Granite Pegmatite)

Ptygmatic Migmatite

Migmatite (consisting of Neosome and Paleosome fractions)

Tumbled quartz-rich stone, likely milky quartz

Quartz (SiO₂), possibly iron-stained milky quartz or quartzite

Granite featuring Quartz Vein

Phaneritic Felsic Igneous Rock (Quartz, Orthoclase Feldspar, Mica)

Sandstone (with vugs)

Arenite / Sedimentary Sandstone

Weathered rock fragment, possibly granite or metamorphic stone

Indeterminate; likely quartz–feldspar–mica aggregate (granite-like), but image resolution prevents reliable identification

Pink feldspar-bearing rock, possibly pink granite or orthoclase

Likely potassium feldspar (orthoclase/microcline), KAlSi₃O₈; exact identification requires testing

Pegmatite with Schorl (Black Tourmaline) and Mica

Pegmatite (complex association of NaAlSi3O8, NaFe3Al6(BO3)3Si6O18(OH)4, and KAl2(AlSi3O10)(OH,F)2)

Granodiorite

Intermediate Phaneritic Plutonic Rock

Dalmation Stone (frequently called Dalmatian Jasper)

Peralkaline Quartz-Feldspar Rock

Dumortierite Quartz

Al7(BO3)(SiO4)3O3

Amazonite in Quartz

K(AlSi3O8) - Potassium Feldspar with Quartz (SiO2)

Porphyritic Basalt River Stone

Porphyritic Basalt

Rounded granite pebble

Granite, chiefly quartz, feldspar, and mica; approximate composition SiO₂-rich felsic rock

Quartz-rich breccia or vein quartz fragment

Quartz (SiO₂), likely with iron-oxide staining and attached host rock

Small pale mineral fragment

Unidentified; possibly quartz, calcite, or feldspar

Polished/tumbled brown-and-white mineral fragment

Indeterminate; possibly quartz-rich jasper, brecciated jasper, or an iron-stained quartz mineral

Sandstone

Sandstone (Siliciclastic Sedimentary Rock)

Tumbled red jasper with a quartz vein

Jasper (microcrystalline quartz, SiO₂), likely crossed by milky quartz

Milky quartz with iron-stained matrix

Quartz (silicon dioxide, SiO₂)

Gneissic granite / granitic gneiss

Quartz–feldspar–mica gneiss; composition commonly quartz (SiO₂), feldspars, and biotite/muscovite

Quartz-rich pegmatite with mica and dark inclusions

Pegmatite; chiefly quartz (SiO₂), with feldspar and biotite/tourmaline inclusions

Amazonite

Microcline (KAlSi3O8) with trace lead (Pb)

Sandstone

Sandstone (Quartzose/Feldspathic Sandstone)

Weathered quartz-rich cobble, possibly quartzite or feldspar-rich granite

Quartz–feldspar aggregate; identification is uncertain from the photograph

Mica-rich metamorphic rock, likely schist

Biotite–muscovite schist, possibly garnet-bearing

Basalt with Feldspar phenocrysts

Aphanitic to Porphyritic Mafic Volcanic Rock

Feldspar-rich igneous rock, likely granite or gneiss fragment

Granite-like quartz–feldspar rock; exact identification is uncertain from the blurred image

Carved Gemstone Mushroom

Quartz / Feldspar composite (Carved lapidary art)

Rounded gray river pebble

Likely weathered granite or granodiorite; exact identification is uncertain from the photograph

Beryl (likely Aquamarine or Heliodor variant)

Beryllium aluminum silicate (Be3Al2Si6O18)

Dalmatian Jasper

Peralkaline Quartz-Feldspar Rock with Arfvedsonite

Porphyritic Rhyolite

Rhyolite (Porphyry)

Amazonite in Matrix

Potassium Feldspar (Microcline), KAlSi3O8