Sandstone (Ferruginous)
Arenite with Iron-Oxide Cement (primarily SiO2 with Fe2O3/FeOOH)
Category
Browse igneous or sedimentary (water worn) specimens identified by the Rock Identifier community.
Sandstone (Ferruginous)
Arenite with Iron-Oxide Cement (primarily SiO2 with Fe2O3/FeOOH)
Sandstone (River Pebble)
Arenite (SiO2 based)
Granite Pegmatite
Phaneritic Felsic Igneous Rock (Granite)
Sandstone (Quartzite Pebble)
Arenite (primarily SiO2)
Sandstone
Arenite (composed primarily of SiO2)
Scoria (Basaltic Lava Rock)
Vesicular Basalt
Scoria (Lava Rock)
Mafic Vesicular Volcanic Rock
Scoria (Volcanic Rock)
Scoria (often basaltic scoria)
Pumice
Pumicite
Rhyolitic Tuff (Breccia Type)
Rhyolitic Pyroclastic Rock (Mixed Silicates including Quartz, Feldspar, and Volcanic Glass)
Tektite (Indochinite)
Tektite (High-silica natural glass)
Granitoid (Granite/Diorite)
Course-grained Plutonic Igneous Rock
Sandstone (specifically Red Sandstone)
Arenite (primarily Quartz, SiO2)
Conglomerate
Conglomerate (SiO2 matrix with various inclusions)
Quartz (Milky/Clear variety)
Silicon Dioxide (SiO2)
Magnetite / Hematite mix (Iron Ore)
Fe3O4 (Magnetite) / Fe2O3 (Hematite)
Magnetite (Lodestone)
Magnetite (Fe3O4)
Chert Pebble with Inclusion
Microcrystalline Quartz (SiO2)
Chert Pebble
Microcrystalline Quartz (SiO2)
Gravel or Pebble
Clastic Sedimentary Grain (typically composed of Quartz or Silicate minerals)
Basalt River Stone
Extrusive mafic igneous rock
Basalt Pebble with Quartz Veining
Basalt (extrusive volcanic rock)
Sandstone (Quartzose Sandstone Pebble)
Arenite (primarily SiO2)
Sandstone (Quartzose Pebble)
Clastic sedimentary rock (primarily SiO2)
Sandstone (Muddy/Silty Variety)
Arenite with high silt/clay content (clastic sedimentary rock)
Rock Salt (Halite)
Halite (Sodium Chloride, NaCl)
Shale
Fissile mudstone (primarily clay minerals and silt-sized quartz)
Satin Spar (Selenite)
Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O
Granite Pebble
Granite (Phaneritic Igneous Rock)
Basalt (Weathered/Tumbled)
Extrusive Mafic Igneous Rock
Granite Pegmatite
Phaneritic Plutonic Igneous Rock
Granitic Pegmatite with Tourmaline
Granite (Feldspar/Quartz matrix) with Schorl (NaFe2+3Al6Si6O18(BO3)3(OH)3OH)
Smoky Quartz and Feldspar Pegmatite
Granitic Pegmatite (chiefly SiO2 and KAlSi3O8)
Granodiorite Pebble
Granodiorite (containing Quartz, Plagioclase Feldspar, and Biotite/Amphibole)
Graphic Granite
Pegmatitic Quartz-Feldspar Granite
Snowflake Obsidian
Volcanic glass with Spherulite inclusions (SiO2)
Granite Pebble
Granite (Phaneritic Quartz-Feldspar intrusive rock)
Red Scoria (Lava Rock)
Scoria (Vesicular Basalt)
Scoria (Lava Rock)
Scoria (Vesicular Basalt)
Bauxite
Bauxite (Al(OH)3 mixed with Fe2O3 and clay minerals)
Glauconitic Sandstone (Greensand)
Glauconitic Sandstone (Iron-potassium phyllosilicate mineral: (K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2)
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)