Lava Rock Substrate
Scoria (Basaltic Rock)
igneous
Category
Rock
Browse rock specimens identified by the Rock Identifier community.
Desert Varnish (on Sandstone)
Rock Varnish (composed of Manganese oxides, Iron oxides, and Clay minerals)
sedimentary
Basalt with Quartz Veins
Aphanitic Mafic Igneous Rock (Main body: SiO2, Fe, Mg rich)
igneous
Agate (Water-Worn)
Cryptocrystalline quartz (SiO2)
sedimentary
Moonstone
Orthoclase Feldspar (KAlSi3O8)
mineral
Sandstone
Arenite (SiO2 based)
sedimentary
Quartz Geode
Silicon Dioxide (SiO2) within a geode
mineral
Migmatite
Migmatite (Mixed metamorphic-igneous rock)
metamorphic
Fluorite on Matrix
Calcium Fluoride (CaF2)
mineral
Vesicular Basalt
Extrusive mafic igneous rock (Basalt with vesicular texture)
igneous
Dalmatian Jasper
Peralkaline Quartz-feldspathic Rock (Arfvedsonite-bearing)
igneous
Porphyritic Basalt (Chinese Flower Stone / Chrysanthemum Stone basalt variety)
Porphyritic Basalt containing Plagioclase Feldspar phenocrysts
igneous
Herkimer Diamond
Quartz (Silicon Dioxide, SiO2)
mineral
Wishing Stone (Basalt or Siltstone with Quartz/Calcite Vein)
Basalt (SiO2+MgO+FeO) or Siltstone with a Quartz (SiO2) or Calcite (CaCO3) vein
igneous or sedimentary
Granite
Granite (composed primarily of Quartz, Feldspar, and Mica/Amphibole)
igneous
N/A - Non-Geological Item
not a rock/mineral
Quartz Pebble (Iron-Stained)
Silicon Dioxide (SiO2)
mineral
Gneiss with Quartz Vein
Gneiss (containing SiO2 vein)
metamorphic
Granite Cobble
Phaneritic Felsic Igneous Rock (primarily Quartz, Feldspar, and Mica)
igneous
Basalt with Plagioclase Feldspar
Basalt (mafic extrusive igneous rock) with plagioclase feldspar phenocrysts
Igneous
Druzy Quartz on Host Rock
Silicon Dioxide (SiO2) with various iron-oxide inclusions
mineral
Shatter Cone
Impactite (Shatter Cone texture)
metamorphic
Vesicular Basalt
Basalt
igneous
Quartz Geode in Sedimentary Host Rock
Silicon Dioxide (SiO2) in Carbonate Matrix
sedimentary
Granite / Gneiss (Felsic Metamorphic or Igneous Rock)
Gneiss (or weathered Granite)
metamorphic
Basalt Pebble
Basaltic Igneous Rock
igneous
Quartz (on matrix)
Quartz (Silicon Dioxide, SiO₂)
Mineral
Basalt (River Rock)
Aphanitic Mafic Igneous Rock
igneous
Rock Fragment with Calcite/Quartz Vein
Polymictic Rock Fragment (SiO2 / CaCO3)
igneous
Ferruginous Sandstone (Ironstone Nodules)
Ferruginous Quartz-Arenite (with Goethite/Hematite cement)
sedimentary
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic volcanic rock)
igneous
River Rock (Quartzite/Chert)
Quartzite (primarily SiO2)
metamorphic
Massive Quartz (Milky or Gray)
Silicon Dioxide (SiO2)
mineral
Quartz with Host Rock
SiO2 (Quartz) with fine-grained Matrix
sedimentary
Chert Geode or Nodule
Microcrystalline Quartz (SiO2)
sedimentary
Druzy Quartz Geode (Oco or Moroccan variety)
Silicon Dioxide (SiO2)
mineral
Basalt (Amygdaloidal)
Amygdaloidal Basalt
igneous
Red Siltstone (or Red Shale)
Clastic Sedimentary Rock (Composition: primarily Quartz, Clay minerals, and Hematite Fe2O3)
sedimentary
Quartz Pebble
Silicon Dioxide (SiO2)
sedimentary
Red Granite Pebble
Intrusive Felsic Igneous Rock (Granite)
igneous
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Fossiliferous Sandstone / Quartzite Pebble
Sedimentary rock with skeletal fragments (e.g., Paleozoic crinoid/brachiopod fossils)
fossil