Mineral In A Matrix (Likely Quartz Or Feldspar)

Feldspar (Granite Pegmatite matrix)

Potassium Feldspar (KAlSi3O8) / Quartz Mixture

Quartz-rich rock, possibly druzy quartz on altered host rock

Quartz (SiO₂), likely with mica/clay minerals and minor iron-oxide staining

Quartz vein in host rock

Quartz (SiO₂) vein cutting an unidentified, likely metamorphic host rock

Schorl (Black Tourmaline) in Quartz and Feldspar

NaFe2+3Al6(Si6O18)(BO3)3(OH)3(OH)

Likely weathered granite or granitic pegmatite

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

Granite

Phaneritic Plutonic Felsic Rock (SiO2, KAlSi3O8, NaAlSi3O8, CaAl2Si2O8)

Tumbled magnetite-bearing rock, likely basalt or gabbro

Magnetite (Fe₃O₄) in a mafic silicate matrix, probably basaltic or gabbroic

Biotite granite (possibly pegmatitic granite)

Granite: quartz (SiO₂), feldspar (KAlSi₃O₈–NaAlSi₃O₈), and biotite mica

Quartz-bearing rock, possibly weathered granite or pegmatite

Quartz–feldspar–mica aggregate; exact classification is uncertain from the image

Polished porphyritic basalt cobble

Basalt, commonly composed of plagioclase feldspar, clinopyroxene, olivine, and opaque iron-titanium oxides

Granite with Epidote / Unakite precursor

Plutonic igneous rock composed of Quartz, Feldspar, and Epidote/Chlorite

Dalmatian Stone (often misnamed Dalmatian Jasper)

Aplite (with hornblende/arfvedsonite inclusions)

Graphic Granite

Pegmatite (Quartz and Alkali Feldspar intergrowth)

Quartz-rich granitic rock (likely granite or granitic pegmatite)

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

Porphyritic granite (likely weathered granitic rock)

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

Pegmatite (Granitic)

Granitic Pegmatite containing Quartz, Feldspar, and Tourmaline (Schorl)

Polished blue spotted stone, likely K2 stone

K2 stone: granite containing blue azurite spots; quartz–feldspar–biotite matrix

Presumed K2 granite (K2 stone)

K2 granite, an altered granitic rock composed mainly of quartz, feldspar, and white mica, with blue azurite spots

Granite Pebble

Granite

Diorite with Quartz Veins

Diorite

Leopardite

Quartz porphyry / Quartz monzonite with manganese oxide spots

Quartz-rich granitic rock (likely pegmatitic granite)

Granite/pegmatite; predominantly quartz (SiO₂), feldspar, and dark biotite or amphibole

Conglomerate (possibly breccia)

Clastic sedimentary rock; chiefly quartz- and feldspar-rich clasts in a weathered iron-oxide cement

Rounded porphyritic volcanic rock, likely andesite or basalt

Porphyritic andesite–basalt; composition commonly plagioclase, pyroxene, and iron-magnesium minerals

Granite or granitic gneiss fragment

Granite: quartz + feldspar + mica; possibly weathered granitic gneiss

Biotite-rich granite or granitic gneiss

Quartz–feldspar–biotite granite; possibly foliated granitic gneiss

Likely granite or granitic gneiss

Granite: quartz + feldspar + mica; possibly foliated into gneiss

Weathered quartz-rich rock, likely granite or quartzite

Indeterminate; probable quartz–feldspar aggregate, possibly granitic gneiss

Dalmatian Stone

Dalmatian Jasper (Aplitic Rock)

Amygdaloidal Basalt with Quartz

Basalt (SiO2 inclusion)

Biotite-bearing granite or granitic pegmatite fragment

Granite/pegmatite; quartz (SiO₂), feldspar, and biotite mica

Polished pink granite (likely granite pebble)

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

Coarse-grained granite or granitic gneiss

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

Quartz-rich pegmatite (likely granite/pegmatite boulder)

Coarse-grained felsic igneous rock, chiefly quartz (SiO₂), feldspar, and minor mica; exact identification requires testing

Quartz-rich granite (likely leucocratic granite)

Granite, composed mainly of quartz and feldspar with minor dark minerals

Milky Quartz in Siltstone or Feldspar

Silicon Dioxide (SiO2)

Likely weathered sandstone or fine-grained granite

Quartz–feldspar-rich lithic rock; exact identification requires a fresh surface and testing

Quartz-rich breccia or conglomerate

Siliciclastic conglomerate/breccia, predominantly quartz and feldspar clasts in a rusty iron-oxide cement

Porphyritic basaltic-andesite cobble

Porphyritic andesite to basaltic andesite; plagioclase-rich volcanic rock

Chrysocolla-bearing rock (likely chrysocolla in a host rock)

Chrysocolla, hydrated copper aluminosilicate: approximately (Cu,Al)₂H₂Si₂O₅(OH)₄·nH₂O

Mica-rich pegmatite (likely muscovite-bearing granite)

Pegmatite; chiefly quartz (SiO₂), feldspar, and muscovite mica

Amethyst cluster

Quartz, purple variety — SiO₂, colored mainly by irradiation and iron-related impurities