Mineral In A Matrix (Likely Quartz Or Feldspar)

Garnet-bearing metamorphic rock, possibly garnet amphibolite or mica schist

Almandine garnet (Fe₃Al₂Si₃O₁₂) in a mafic, amphibole–feldspar-rich matrix

Biotite-rich gneiss (possibly mica schist)

Quartz–feldspar–biotite gneiss; mica-rich metamorphic rock

Dalmatian Jasper

Dalmatian Stone (Arfvedsonite/Albite Microquartz)

Porphyritic rhyolite (likely weathered volcanic rock)

Rhyolite, a volcanic equivalent of granite; chiefly quartz and alkali feldspar in a fine-grained groundmass

Porphyritic Granite pebble (or Porphyry)

Porphyritic Plutonic Igneous Rock (Granite / Monzonite porphyry)

Graphic Granite

Graphic Granite (a runic intergrowth of Quartz and Feldspar)

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

Pink granite

Granite, chiefly quartz–alkali feldspar–plagioclase with biotite/hornblende

Green Spot Jasper (Kiwi Jasper / Sesame Jasper)

Partially altered granitic rock rich in quartz, microcline feldspar, and tourmaline or amphibole inclusions

Conglomerate

Clastic Sedimentary Rock (Conglomerate)

Polished granite

Granite; chiefly quartz, feldspar, and mica/amphibole

Porphyritic Granite (Glacial Erratic)

Porphyritic Biotite Granite

Likely milky quartz fragment

Quartz (silicon dioxide, SiO₂), possibly with iron-oxide or mica inclusions

Granite Pebble

Phaneritic Felsic Igneous Rock (Granite)

Quartz Vein in Matrix (Gneiss/Schist)

Silicon Dioxide (SiO2) in Metamorphic Rock Matrix

Greywacke with Quartz Veins

Lithic Sandstone (Greywacke) with SiO2 inclusions

Lepidolite in Quartz Matrix

K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2

Porphyritic Basalt (River Rock)

Porphyritic Basalt

Uncertain polished mineral specimen

Indeterminate; possibly quartz or feldspar with iron-oxide staining

Pegmatitic granite (likely garnet-bearing)

Coarse-grained granite/pegmatite; quartz + feldspar ± biotite/hornblende and almandine garnet

Porphyritic Basalt

Porphyritic Mafic Volcanic Rock

Milky quartz (likely quartz fragment)

Quartz, silicon dioxide (SiO₂)

Granite Pebble

Felsic Intrusive Igneous Rock

Weathered granitic rock fragment

Granite, predominantly quartz–feldspar–mica assemblage

Weathered granite-like rock

Granite, likely biotite-bearing; exact identification requires testing

Rhyolite

Rhyolite (felsic extrusive igneous rock)

Clear Quartz Crystal on Matrix

SiO2 (Silicon Dioxide)

Porphyritic Rhyolite

Porphyritic Rhyolite (Felsic volcanic rock)

Weathered granite or granitic gneiss

Granite: quartz, feldspar, and mica; possibly weakly foliated gneiss

Sandstone (Ferruginous)

Arenite with Iron Oxide (Fe2O3) cement

Quartz-rich granitoid pebble, likely granite or granitic gneiss

Granite: quartz + feldspar (orthoclase/plagioclase) + minor mica; possibly gneiss if foliated

Porphyritic granite or granitic gneiss

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

Porphyritic basalt (likely amygdaloidal basalt)

Basalt containing larger plagioclase crystals and pale vesicle-fill minerals, commonly calcite, zeolite, or quartz

Quartz Vein in Host Rock (clastic sediment)

Silicon Dioxide (SiO2) in matrix

Beryl in Quartz Matrix

Beryllium Aluminum Silicate (Be3Al2Si6O18)

Granite Cobble

Phaneritic Felsic Igneous Rock

Gneiss

Feldspar–quartz–mica gneiss, locally amphibole-bearing

Granite Pebble

Granite (Plutonic Igneous Rock)

Small gray rock fragment, likely granite or diorite

Uncertain; probable coarse-grained silicate rock dominated by feldspar and quartz, possibly biotite/hornblende

K2 Jasper (K2 Granite)

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

Porphyritic volcanic rock, likely andesite

Porphyritic andesite; mainly plagioclase, pyroxene/amphibole, and volcanic groundmass