Uncertain fine-grained rock or mineral-bearing specimen
Indeterminate; possible quartz- or feldspar-bearing matrix with reflective grains
Category
Browse industrial byproduct specimens identified by the Rock Identifier community.
Uncertain fine-grained rock or mineral-bearing specimen
Indeterminate; possible quartz- or feldspar-bearing matrix with reflective grains
Likely weathered river pebble
Indeterminate lithology; possibly fine-grained sandstone, siltstone, or chert
Pebble
Lithic fragment / Water-worn rock
Sandstone / Quartzite
Sedimentary quartz arenite
Quartz with Feldspar and Mica (Pegmatite Fragment)
Granitic Pegmatite
Quartz Crystal Fragment
Silicon Dioxide (SiO2)
Quartz (Smoky Quartz / Calcite)
SiO2 (Silicon Dioxide)
Muscovite Mica
KAl2(AlSi3O10)(OH)2
Pegmatite (Quartz, Feldspar, and Tourmaline/Biotite)
Pegmatitic Igneous Rock
Pegmatite (Quartz and Feldspar)
Igneous Pegmatite containing SiO2 and KAlSi3O8
Agate
Silicon dioxide (Chalcedony), SiO2
Coal
Bituminous Coal / Anthracite
Coal
Bituminous Coal / Anthracite
Garnet
Almandine/Pyrope Garnet (Silicate Mineral Group)
Almandine Garnet
Almandine, Fe3Al2(SiO4)3
Sandstone Pebble
Arenite (Siliclastic sedimentary rock)
Sandstone (Ferruginous)
Clastic sedimentary rock (primarily SiO2 with Fe2O3 cement)
Quartzite Pebble
Metamorphosed Silicon Dioxide (SiO2)
Sandstone
Arenite
Gold-bearing Quartz / Auriferous River Rock
Lode Gold in Quartz Matrix (SiO2 + Au)
Quartzite with Quartz Veining
Metamorphosed Quartz-rich Sandstone (SiO2)
Peridotite (Olivine Rock)
Peridotite (composed largely of olivine, (Mg, Fe)2SiO4)
Garnet (Almandine)
Almandine (Fe3Al2(SiO4)3)
Quartzite Cobble
Quartzite (SiO2)
Red Sandstone
Ferruginous Sandstone (SiO2 dominated with Fe2O3)
Lava Rock (Basaltic Scoria)
Vesicular Basalt
Garnet in Quartzite
Garnet-bearing Quartzite (SiO2 + X3Y2(SiO4)3)
Red Sandstone
Sandstone (lithic arenite or arkose with iron oxide)
Quartzite Pebble
SiO2 (Silicon Dioxide)
Basalt (Weathered)
Mafic Igneous Rock
Cubic Zirconia (Jewelry Setting)
Cubic Zirconia (ZrO2)
Black Tourmaline (Schorl)
Schorl (NaFe3Al6(BO3)3Si6O18(OH)4)
Diamond (or Diamond Simulant)
Carbon (C)
Smoky Quartz (Rough)
Silicon Dioxide (SiO2)
Sandstone (likely Siltstone or Mudstone)
Clastic sedimentary rock (primarily SiO2 with various oxides)
Limestone
Calcium Carbonate (CaCO3)
Quartz Pebble
Silicon Dioxide (SiO2)
Quartz with Iron Staining
Crystalline Silicon Dioxide (SiO2)
Pink Garnet (likely Almandine or Rhodolite)
Garnet Group (Fe3Al2(SiO4)3 to Mg3Al2(SiO4)3)
White Marble
Recrystallized Calcite (CaCO3)
River Quartz Cobble
Silicon Dioxide (SiO2)
Diamond
C (Carbon)