Mineral In A Matrix (Likely Quartz Or Feldspar)

Graphic Granite

Graphic Granite (a runic intergrowth of Quartz and Feldspar)

Iron-stained quartz-rich rock, possibly weathered granite or pegmatite

Quartz–feldspar-rich rock with iron-oxide staining; exact rock type cannot be determined from the image

Dalmatian jasper (likely orbicular microgranite)

Quartz–feldspar–biotite/pyroxene microgranite; commonly marketed as Dalmatian jasper

Epidote in Quartz

Epidote (Ca2(Al,Fe)3(SiO4)3(OH)) in Quartz (SiO2)

Garnet Amphibolite (or Garnet Gneiss)

Garnet amphibolite / Garnet-bearing metamorphic rock

Quartz / Calcite Vein Rock

Silicon Dioxide (SiO2) or Calcium Carbonate (CaCO3)

Porphyry

Porphyritic Andesite / Basaltic Porphyry

Quartz-rich granite pebble

Granite, composed mainly of quartz, feldspar, and mica

Basalt with Quartz Infill

Basalt (Mafic Extrusive Volcanic Rock)

Quartz Vein in Siltstone

SiO2 (Quartz) on clastic sedimentary matrix

Quartz-rich pegmatite with mica

Granitic pegmatite; chiefly quartz (SiO₂), feldspar, and muscovite/biotite mica

Polished porphyritic volcanic rock (likely rhyolite or andesite)

Porphyritic rhyolite–andesite; fine volcanic groundmass with abundant pale feldspar phenocrysts and possible vesicles

Tumbled yellow granite or granitic gneiss

Granite, chiefly quartz, feldspar, and biotite/amphibole

Weathered quartz-rich sandstone or granitic rock

Indeterminate; likely iron-stained quartz sandstone, possibly weathered granite

Weathered porphyritic volcanic rock (likely andesite or basalt)

Aphanitic to porphyritic andesite–basalt; composition commonly plagioclase, pyroxene, and minor iron oxides

Pink granite or granitic gneiss

Coarse-grained quartz–feldspar–mica rock; likely granite, possibly weathered gneiss

Weathered red-and-green metamorphic rock

Probable epidote-amphibolite or altered schist; exact identification requires testing

Likely amphibolite

Amphibolite, composed mainly of hornblende and plagioclase feldspar

K2 Jasper (K2 Granite)

Granite with Azurite inclusions (SiO2 + Cu3(CO3)2(OH)2)

Sandstone with Quartz Sphere

Arenite (SiO2-rich sedimentary rock) with Quartzite/Rose Quartz sphere

Dalmatian jasper (likely orbicular rhyolite)

Silica-rich rhyolite, commonly sold as Dalmatian jasper; typically quartz, feldspar, and dark amphibole/biotite inclusions

Weathered granite or granitic gneiss pebble

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

Basalt with Quartz Veining

Veined Basalt (composed primarily of plagioclase feldspar, pyroxene, and olivine with quartz/calcite infill)

Granite

Granite (a common term for a felsic intrusive igneous rock)

Leopardite

Porphyritic Quartz Monzonite or Rhyolite

Layered sandstone

Quartz-rich sandstone, likely arkosic or lithic sandstone

Weathered granite

Granite, chiefly quartz, potassium feldspar, plagioclase, and biotite or hornblende

Porphyritic Andesite/Basalt or Diorite River Rock

Porphyritic Igneous Rock

Rhyolite or jasper-bearing volcanic rock

Rhyolite, likely altered and silicified; red coloration may come from hematite

Feldspar in Matrix

Feldspar group minerals in metamorphic or igneous matrix

Quartz-rich pegmatite

Granitoid pegmatite; predominantly quartz (SiO₂), with abundant feldspar and probable mica

Granite cobble

Granite, a coarse-grained felsic intrusive igneous rock

Granite Pebble

Granite (Plutonic Igneous Rock)

Rounded, porphyritic volcanic pebble (likely andesite)

Porphyritic andesite; exact identification requires examination or testing

Pebble (likely Quartz or Chert)

SiO₂ (Silicon Dioxide) - referring to the likely main mineral composition, Quartz. If it's chert, the scientific name remains SiO₂ with a microcrystalline structure.

Quartz-rich pegmatitic rock with possible epidote or chlorite

Hydrothermal/pegmatitic quartz-bearing rock; identifiable minerals may include quartz (SiO₂), feldspar, and epidote/chlorite

Quartz Vein in Basalt or Porphyry

Silicate-veined volcanic rock

Pegmatitic granite (quartz–feldspar rock)

Coarse-grained granitic pegmatite, chiefly quartz and feldspar with minor mica

Porphyritic granite or granitic gneiss

Quartz–feldspar–biotite granite; possibly foliated into granitic gneiss

Granite (likely)

Coarse-grained felsic intrusive igneous rock, principally quartz and feldspar with dark mica or amphibole

Amygdaloidal Basalt

Basalt with secondary amygdule minerals (likely Epidote or Chlorite)

Conglomerate

Clastic Sedimentary Rock (Conglomerate)