Granite Pebble
Phaneritic intrusive igneous rock
Category
Browse organic materia (not a rock or mineral) specimens identified by the Rock Identifier community.
Granite Pebble
Phaneritic intrusive igneous rock
Glaucophane / Blue Schist
Glaucophane (Na2(Mg3Al2)Si8O22(OH)2)
Chert (and Flint)
Silicon Dioxide (SiO2)
Granite
Intrusive igneous rock composed mainly of quartz, alkali feldspar, and plagioclase
Granite
Phaneritic Felsic Intrusive Igneous Rock
Schist
Mica Schist (primarily consisting of muscovite KAl2(AlSi3O10)(OH)2 or biotite K(Mg,Fe)3(AlSi3O10)(OH)2)
Greywacke (River Pebble with Quartz Veins)
Greywacke (Indurated Sandstone); Veins: SiO2 (Quartz)
Granite
Felsic intrusive igneous rock
Granite
Intrusive Igneous Rock
Mixed mineral and rock collection
Predominantly quartz varieties, including amethyst, plus likely calcite, feldspar, mica, and miscellaneous polished stones
Sandstone
Arenite (predominantly SiO2)
Quartz Druzy on Matrix
Silicon Dioxide (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Generic Pebble / Rock Fragment
Lithic fragment / Weathered rock
Sandstone (Quartzose)
Arenite (primarily SiO2)
Basalt
Extrusive Igneous Rock
Sandstone
Clastic Sedimentary Rock
Sandstone
Sedimentary Rock (Quartz arenite / Lithic sandstone)
Fossilized Plant or Tree Bark
Lepidodendron or Sigillaria (example genera)
Sandstone
Arenite (primarily Quartz-rich)
Sandstone
Arenite (SiO2 primarily)
Herkimer Diamond
Quartz (Silicon Dioxide, SiO2)
Jasper
Microcrystalline Quartz (SiO2)
Sandstone (likely Quartzose Sandstone)
Arenite (primarily SiO2)
Sandstone
Arenite (primarily SiO2)
Sandstone
Arenite (primarily SiO2)
Sandstone
Arenite (primarily SiO2)
Sandstone
Arenite
Jasper Pebble
SiO2 (Microcrystalline Quartz)
Hematite
Iron(III) oxide (Fe2O3)
Granite
Phaneritic Plutonic Felsic Rock
Chert
Chert (Microcrystalline Quartz, SiO2)
Agate
Agate (Silicon Dioxide, SiO2)
Jasper
Silicon Dioxide (Microcrystalline Quartz, $SiO_2$)
Chert / Flint
Silicon dioxide (SiO2)
Chert (Flint)
Silicon Dioxide (SiO2)
Chert (Jasper/Chalcedony)
Microcrystalline Quartz (SiO2)
Banded Gneiss
Gneiss (Metamorphic Rock)
Granite
Phaneritic plutonic felsic rock (primarily Quartz, Feldspar, and Mica)
Septarian Nodule
Septarian Concretion (Calcite, Aragonite, and Limestone)
Cannonball Concretion
Calcite-cemented Sandstone Concretion
Chert (variations include Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)