Brown Sandstone Pebble
Clastic Sandstone (SiO2 with iron oxides)
Category
Browse man made material specimens identified by the Rock Identifier community.
Brown Sandstone Pebble
Clastic Sandstone (SiO2 with iron oxides)
Granite
Phaneritic Igneous Rock (primarily Quartz, Feldspar, and Mica)
Milky Quartz Pebble
Crystalline Silicon Dioxide (SiO2)
Granite
Felsic Plutonic Rock (Granite)
Chert (Yellow Jasper variant)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Rough Diamond
Diamond (Native Carbon), C
Diamond (Princess Cut)
Carbon (C)
Banded Calcite (often sold as 'Mexican Onyx' or 'Green Onyx')
Calcite (Calcium Carbonate, CaCO3)
Petrified Wood (Agatized/Silicified Wood)
Silicified Wood (SiO2)
Calligraphy Stone
Fossiliferous Stromatolite Limestone (also known as Arabic Script Stone, Miriam Stone, or Elephant Skin Jasper)
Serpentinite
Serpentinite (composed primarily of Serpentine group minerals: (Mg,Fe)3Si2O5(OH)4)
Tufa
Calcareous Tufa (CaCO3)
Chert (with Manganese Dendrites)
Chert (Cryptocrystalline Quartz, SiO2)
Granite
Granite (Felsic Plutonic Rock)
Sandstone
Arenite (lithic or quartz sandstone)
Chert (often called Flint when dark)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Fossil Coral
Scleractinia (Anthos), primarily Calcium Carbonate (CaCO3)
Sandstone with Manganese Oxide Patina
Clastic Sedimentary Rock (primarily SiO2)
Sandstone
Arenite (SiO2 principal)
Weathered reddish-brown rock fragment
Probably altered basalt or fine-grained volcanic rock; exact identification requires testing
Granite
Felsic intrusive igneous rock
Granite
Felsic Plutonic Rock
Granite
Felsic Intrusive Igneous Rock
Granite Pebble
Igneous Intrusive Rock (Quartz-Feldspar-Mica Phenocrysts)
Granite
Granite (Phaneritic Igneous Rock)
Blue-green turquoise-like tumbled stone
Turquoise, hydrous copper aluminum phosphate: CuAl₆(PO₄)₄(OH)₈·4H₂O
Polished pink granite cobble
Granite, chiefly potassium feldspar, plagioclase, quartz, and biotite/hornblende
Banded Sandstone
Arenite (composed primarily of Quartz: SiO2)
Stichtite in Serpentine (Atlantisite)
Mg6Cr2CO3(OH)16·4H2O (Stichtite) within Mg3Si2O5(OH)4 (Serpentine)
Red Sandstone
Arenite (primarily Quartz SiO2 with Hematite Fe2O3 cement)
Basalt
Basalt (Aphanitic Mafic Igneous Rock)
Quartz geode or drusy quartz cluster
Quartz (silicon dioxide, SiO₂), likely microcrystalline quartz lining a cavity
Red Sandstone
Arenite (primarily Quartz with Hematite cement)
Basalt
Basalt (Aphanitic Mafic Igneous Rock)
Petrified Wood
Silicified Wood (SiO2)
Limonite (Iron Stone Concretion)
Limonite (Hydrous Iron Oxide) - FeO(OH)·nH2O
Diamond
Carbon (C)
Serpentine
Antigorite/Chrysotile/Lizardite (Mg,Fe)3Si2O5(OH)4
Cubic Zirconia
Zirconium Dioxide (ZrO2)
Chert (Jasper/Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Quartzite
Metamorphic Quartzite (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)