Blue Agate (Dyed Chalcedony)
Silicon Dioxide (SiO2)
mineral
Category
Not A Natural Rock (Man Made Composite)
Browse not a natural rock (man made composite) specimens identified by the Rock Identifier community.
Milky Quartz (with Iron Oxide staining)
Silicon Dioxide (SiO2)
mineral
Emerald
Beryl (Be3Al2(SiO3)6) with Chromium/Vanadium impurities
mineral
Sandstone (likely Quartzose)
Arenite (SiO2 principal mineral)
sedimentary
Serpentine
Serpentine Group (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4
metamorphic
Sandstone (Quartzose Sandstone)
Arenite (primarily SiO2)
sedimentary
Botryoidal Chalcedony with Calcite
Chalcedony (SiO2 with accessory minerals, likely CaCO3)
Mineral
Basalt
Extrusive Mafic Igneous Rock (composed primarily of plagioclase feldspar and pyroxene)
igneous
Pearl
Calcium carbonate (CaCO3) - mainly Aragonite with Conchiolin
mineraloid
Sandstone (likely Quartzose Sandstone pebble)
Arenite (primarily SiO2)
sedimentary
Basalt
Basalt (Composition primarily Plagioclase feldspar, Pyroxene, and Olivine)
igneous
Limestone (Buff/Tan)
Calcium Carbonate (CaCO3)
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Sandstone (with Iron Staining)
Clastic Sedimentary Rock (primarily Quartz, SiO2)
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Sandstone (with Iron Staining)
Clastic sedimentary rock (High Silica / Iron Oxide)
sedimentary
Agate (Moss or Plume Agate variety)
Silicon Dioxide (SiO2)
mineral
Red Hematite
Iron(III) oxide (Fe2O3)
mineral
Limestone
Calcium carbonate (CaCO3)
sedimentary
Sandstone (with Manganese staining)
Arenite (composed primarily of SiO2)
sedimentary
Crushed Limestone Aggregate
Limestone (Calcium Carbonate, CaCO3)
sedimentary
Beach Agate (Chalcedony)
Silicon Dioxide (SiO2)
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Chert (specifically Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
River Rock (Quartz-dominated)
Silicon Dioxide (SiO2) mixture with varied clastic sediments
sedimentary (alluvial deposit)
Sandstone (Ferruginous)
Arenite (primarily SiO2 with Fe2O3 staining)
sedimentary
Granite
Phaneritic Plutonic Igneous Rock (composed of quartz, alkali feldspar, and plagioclase)
igneous
Pearl (Biogenic Mineral)
Calcium Carbonate (primarily Aragonite) with Conchiolin; CaCO3
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Halite (Rock Salt)
Halite; NaCl (Sodium Chloride)
Mineral
Fossil Shell Fragment (possibly Brachiopod or Bivalve)
Calcium Carbonate (CaCO3) - Phylum Brachiopoda or Mollusca
sedimentary
Sandstone
Arenite (primarily composed of SiO2 - Silicon Dioxide)
sedimentary
Limestone (specifically Tufa or Travertine)
Calcium Carbonate (CaCO3)
sedimentary
Quartz (likely macrocrystalline variety)
Quartz (SiO₂)
Mineral
Sandstone
Arenite (primarily SiO2)
sedimentary
Granite
Granite (Felsic Plutonic Rock)
igneous
Milky Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
mineral
Fossiliferous Limestone (Coquina / Shell Limestone)
Biogenic Limestone (CaCO3)
sedimentary
Granite
Granite (Mainly Quartz, Feldspar, and Mica)
igneous
Sandstone (likely Graywacke or Lithic Sandstone)
Clastic Sedimentary Rock
sedimentary
Sandstone
Arenite
sedimentary
Sandstone (likely Graywacke or Arkose variant)
Clastic Sedimentary Rock (Lithic Sandstone)
sedimentary