Basalt
Mafic volcanic rock (primarily plagioclase, pyroxene, and olivine)
Igneous
Category
Not A Rock (Man Made Origin)
Browse not a rock (man made origin) specimens identified by the Rock Identifier community.
Basalt with Iron Oxidation (Lattice/Veined)
Mafic Volcanic Rock (principally Plagioclase and Pyroxene)
igneous
Sandstone
Arenite (primarily SiO2)
sedimentary
Basalt
Mafic Igneous Rock (composed primarily of plagioclase feldspar and pyroxene)
Igneous
Porphyritic Basalt (with Pyrolusite or Iron-oxide staining)
Porphyritic Basalt (Mafic Extrusive)
igneous
Porphyritic Basalt
Porphyritic Basalt (with Plagioclase phenocrysts)
igneous
Sandstone (lithic wacke)
Arenite / Lithic Wacke (mostly SiO2 with rock fragments)
sedimentary
Sandstone
Arenite (SiO2 based with various mineral cements)
sedimentary
Agate Geode with Quartz Druzy
Chalcedony (SiO2) and Quartz (SiO2)
mineral
Druzy Quartz on Chert/Siltstone
Silicon Dioxide (SiO2) on Microcrystalline Silica/Siltstone matrix
sedimentary
Glazed Ceramic Tile
Fused Silicate-Clay composite
Synthetic (Man-made material mimicking natural stone)
Dyed Quartzite
Metamorphosed Quartz (SiO2) with synthetic pigment
metamorphic
Granite
Plutonic felsic rock (Quartz, Feldspar, Mica)
igneous
Basalt with Quartz/Calcite Veins
Amygdaloidal Basalt (SiO2 or CaCO3 inclusions)
igneous
Basalt with Calcite Veins
Basalt (containing CaCO3 inclusions)
igneous
Unidentified Rock Fragment
Unknown
Rock
Herkimer Diamond
Quartz (Silica - SiO2)
mineral
Veined Pebble (likely a Quartz-Veined Pebble)
Pebble with Mineral Vein (e.g., Quartz Vein in a Chert/Mudstone Pebble)
Sedimentary Rock (possibly conglomerate or breccia with a quartz vein)
Quartz Vein in Host Rock
Hydrothermal Quartz (SiO2) in Slates/Schists
metamorphic
Vesicular Basalt with Quartz/Chalcedony
Vesicular Basalt (primarily Plagioclase, Pyroxene, and Olivine with SiO2 infill)
igneous
Unakite
Epidotized Granite
metamorphic
Porphyritic Basalt (River Rock)
Porphyritic Basalt
igneous
Quartz Vein in Gneiss or Basalt
Milky Quartz (SiO2) within Metamorphic Host Rock
Metamorphic or Igneous with Mineral Inclusion
River Rocks (Black)
Various lithologies (e.g., basalt, chert, obsidian for black varieties), mechanically rounded clasts
Sedimentary
Sandstone (with potentially high Feldspar/Arkose content)
Clastic sedimentary rock (SiO2 dominated)
sedimentary
Larimar
Pectolite (a variety of pectolite, NaCa2Si3O8(OH))
Mineral
Sandstone (likely Arkosic)
Clastic Sedimentary Rock
sedimentary
Druzy Quartz on Matrix (likely Limestone or Sandstone)
Silicon Dioxide (SiO2) with various trace impurities
Mineral on Sedimentary Rock
Fossiliferous Sandstone (with Brachiopod or Bivalve mold)
Clastic Sedimentary Rock with Macrofossil Mold
sedimentary
Breciated Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Shale
Lutaceous sedimentary rock
sedimentary
Shale
Fissile mudstone (Shale)
sedimentary
Ironstone Concretion (Ironstone Gourd)
Limonite/Goethite Concretion (FeOO(H))
sedimentary
Sandstone (Quartzose)
Arenite (primarily SiO2)
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Dark-colored Igneous Rock (likely Basalt or Diabase)
Basalt (extrusive igneous) or Diabase (intrusive igneous)
Igneous Rock
Grey Limestone Pebble
Limestone (Calcium Carbonate - CaCO3)
sedimentary
Sandstone (likely Greywacke or Lithic Sandstone)
Arenite / Wacke
sedimentary
Shale or Slate with Quartz Veins
Shale (fine-grained clastic sedimentary rock) or Slate (low-grade metamorphic rock formed from shale) with Quartz (SiO2) veins
Metamorphic, likely Sedimentary with Quartz veins
Quartz Vein Rock
Quartz (Silicon Dioxide, SiO2)
igneous
Chert Breccia (Yellow Jasper)
Silicon Dioxide (SiO2) - Brecciated Chert
sedimentary
Slickenside
Tectonic Fault Scarp Surface
metamorphic