Red Sandstone (Arkose)
Clastic Sedimentary Rock (Lithic Arkose)
sedimentary
Category
Synthetic Material (Not A Rock Or Mineral)
Browse synthetic material (not a rock or mineral) specimens identified by the Rock Identifier community.
Learn about Synthetic Material (Not A Rock Or Mineral) in the encyclopedia
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White chalcedony or quartz-rich pebble
Microcrystalline quartz (SiO₂), possibly with minor calcite or feldspar
mineral
Banded Gneiss
Gneiss (High-grade Metamorphic Rock)
metamorphic
Sandstone
Arenite (SiO2 principal component)
sedimentary
Peridot (Olivine)
Olivine ((Mg, Fe)2SiO4)
mineral
Pink Granite
Phaneritic Felsic Igneous Rock (composed of orthoclase, quartz, and plagioclase)
igneous
Sandstone
Arenite (SiO2 primarily)
sedimentary
Fossilized Shell Impression / Siltstone Fossil
Bivalvia / Brachiopoda mold in Siltstone
fossil
Sandstone
Arenite
sedimentary
Sandstone (Quartzose)
Arenite (primarily SiO2)
sedimentary
Sandstone (Yellow/Tan)
Clastic sedimentary rock (primarily SiO2 with iron oxide staining)
sedimentary
Quartz (Grain)
Silicon Dioxide (SiO2)
mineral
Weathered, iron-stained quartz-rich pebble (uncertain identification)
Microcrystalline quartz, SiO₂, with iron-oxide/hydroxide staining and dark matrix inclusions
mineral
Fossilized Bone
Vertebrate fossil (mineralized bone)
fossil
Bauxite
Aluminum ore (mixture of gibbsite Al(OH)3, boehmite γ-AlO(OH), and diaspore α-AlO(OH))
sedimentary
Likely schist, possibly serpentinite
Mica schist; potential chlorite–serpentine-rich metamorphic rock
metamorphic
Quartz Pebble
Silicon Dioxide (SiO2)
sedimentary
Marble
Recrystallized Carbonate Rock (CaCO3)
metamorphic
Petrified Wood
Silicified Wood (SiO2)
fossil
Turquoise in Matrix
CuAl6(PO4)4(OH)8·4H2O
gemstone
Red Sandstone
Arenite (Ferruginous Sandstone)
sedimentary
Snowflake Obsidian
Volcanic glass containing Spherulitic Cristobalite (SiO2)
igneous
Sandstone
Arenite (Siliclastic sedimentary rock)
sedimentary
Likely quartz-rich metamorphic rock (quartzite or milky quartz)
Quartzite; predominantly quartz (SiO₂), possibly with feldspar and iron-oxide staining
metamorphic
Granite Gneiss
Gneiss (high-grade metamorphic rock)
metamorphic
Sandstone
Arenite (SiO2 based)
sedimentary
Diorite
Diorite (Intermediate intrusive igneous rock)
igneous
Quartz pebble in concrete
Quartz (SiO₂), embedded in Portland-cement concrete
mineral
Sandstone
Arenite (primarily composed of SiO2 - Silicon Dioxide)
sedimentary
Brown Sandstone
Arenite (primarily Quartz and Feldspar, with Iron Oxide cement)
sedimentary
Quartz geode or drusy quartz cluster
Quartz (silicon dioxide, SiO₂), likely microcrystalline quartz lining a cavity
mineral
Sandstone
Arenite (primarily SiO2 - Silicon Dioxide)
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Granite River Rock
Phaneritic Felsic Igneous Rock (Granite)
igneous
Sandstone with Iron Staining
Arenite (SiO2 with Fe-oxide coatings)
sedimentary
Shale
Shale (Lutite)
sedimentary
Dinosaur Fossil Tooth
Vertebrate Fossilized Tooth
fossil
Sandstone
Arenite (primarily SiO2)
sedimentary
Sandstone
Arenite (composed primarily of SiO2)
sedimentary
Sandstone (with banding/weathering)
Clastic Sedimentary Rock (primarily SiO2)
sedimentary
Copper Ore with Malachite and Chalcocite
Copper-bearing Mineral Assemblage (Cu2CO3(OH)2 + Cu2S)
mineral
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
mineral