Sandstone (Quartzose Sandstone)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Category
Man Made Material, Not A Natural Rock Or Mineral Specimen
Browse man made material, not a natural rock or mineral specimen specimens identified by the Rock Identifier community.
Learn about Man Made Material, Not A Natural Rock Or Mineral Specimen in the encyclopedia
View all →
Dyed Pink Agate
Silicon Dioxide (SiO2) - variety Chalcedony
mineral
Polished orbicular jasper (likely ocean jasper)
Silicified microcrystalline quartz/chalcedony (SiO₂), with iron-oxide and other mineral inclusions
gemstone
Graphic Granite
Pegmatitic Granite (Quartz and Microcline K-Feldspar mixture)
igneous
Limonite Geode / Ironstone Nodule
Hydrated Iron Oxide Hydroxide (FeO(OH)·nH2O)
mineral
Likely serpentinized ultramafic rock (serpentinite)
Serpentinite; chiefly serpentine-group minerals, Mg₃Si₂O₅(OH)₄, possibly with magnetite, chromite, and brucite
metamorphic
Porphyry (likely Porphyritic Andesite or Basalt)
Porphyritic Igneous Rock
igneous
Vesicular basalt
Basalt, typically composed of plagioclase feldspar, pyroxene, and minor olivine or iron oxides
igneous
Sunstone
Oligoclase or Andesine (Plagioclase Feldspar) - (Ca, Na)((Al, Si)2Si2O8)
mineral
Smoky Quartz Geode
Silicon Dioxide (SiO2)
mineral
Travertine (Tufa)
Chemical Sedimentary Rock / Travertine (CaCO3)
sedimentary
Scoria
Vesicular Mafic Igneous Rock
igneous
Limonitic Iron Ore / Goethite
Hydrated Iron(III) oxide-hydroxide (primarily FeO(OH)·nH2O)
sedimentary
Rounded pale quartz-rich pebble
Likely milky quartz or quartzite (SiO₂); exact identification is uncertain from the photograph
mineral
Tumbled pale greenish stone, likely serpentine or altered limestone
Probable serpentine-group rock (antigorite/lizardite), possibly serpentinite; identification is visual only
metamorphic
Silty Shale
Silty Shale (Fissile Sedimentary Rock)
sedimentary
Amethyst
Silicon Dioxide (SiO2)
mineral
Fossilized Bone
Permineralized Bone (Vertebrate Fossil)
fossil
Granite Water-Worn Pebble
Intermediate to Felsic Phaneritic Igneous Rock
igneous
Green Quartzite / Quartz Pebble
SiO2 (Silicon Dioxide with inclusions)
metamorphic
Coquina / Fossiliferous Limestone
Calcareous bioclastic sedimentary rock (CaCO3)
sedimentary
Sandstone Cobble
Arenite (Sandstone)
sedimentary
Amethyst Cluster
Silicon Dioxide (SiO2) with iron impurities
mineral
Emerald in Matrix
Beryl (Be3Al2Si6O18) containing Chromium/Vanadium impurities
mineral
Sandstone (Quartzose Sandstone)
Clastic Sedimentary Rock (primarily SiO2)
sedimentary
Pearl
Calcium Carbonate (CaCO3) with Conchiolin
mineral
Sandstone (Ferruginous)
Arenite (variable SiO2 with Fe2O3 staining)
sedimentary
Fossilized oyster or bivalve shell
Fossil Gryphaeidae or Ostreoidea; calcitic shell, CaCO₃
fossil
Sandstone (with potential fossil inclusions)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Tumbled jasper (likely ocean or orbicular jasper)
Microcrystalline quartz (chalcedony), SiO₂, with iron oxides and dark accessory minerals
mineral
Chrysocolla (Copper Ore matrix)
Chrysocolla (Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O)
mineral
Ironstone Nodule
Ferruginous Sandstone / Limonite Concretion
sedimentary
Chert (Green Chert or Jasper)
Microcrystalline Quartz (SiO2)
sedimentary
Sandstone (with banding/weathering)
Clastic Sedimentary Rock (primarily SiO2)
sedimentary
Sandstone Cobble
Arenite (Secondary classification based on grain size)
sedimentary
Basalt and weathered granite-like rock
Dark specimen: basalt, likely vesicular or fine-grained mafic volcanic rock; tan specimen: uncertain, possibly weathered granite or iron-stained felsic rock
igneous
Iron-rich concretion or weathered ironstone
Goethite–hematite limonite aggregate; commonly described as limonite or ironstone
sedimentary
Granodiorite
Intrusive Igneous Rock
igneous
Chert (Nodule)
Chert (SiO2)
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Rough Diamond
Native Carbon (C)
mineral
Sunstone (Aventurine Feldspar)
(Ca,Na)((Al,Si)2Si2O8) with inclusions of Cu or Fe2O3
mineral