Ironstone (Limonitic/Hematitic Sandstone)
Ferruginous sandstone (predominantly Fe2O3 and FeO(OH))
sedimentary
Category
Industrial Byproduct (Anthropogenic Rock Like Material)
Browse industrial byproduct (anthropogenic rock like material) specimens identified by the Rock Identifier community.
Learn about Industrial Byproduct (Anthropogenic Rock Like Material) in the encyclopedia
View all →
Anthracite Coal
Anthracite
sedimentary
Quartz geode (likely amethyst-bearing)
Silica geode; quartz, SiO₂, with possible amethyst and minor iron oxides
mineral
Chert (Flint)
Chert (SiO2)
sedimentary
Basalt
Basalt
igneous
Small pale stone fragment (undetermined)
Unidentified; the image lacks diagnostic detail for a reliable identification
mineral
Pegmatite (Granitic)
Granitic Pegmatite containing Quartz, Feldspar, and Tourmaline (Schorl)
igneous
Schist
Mica Schist
Metamorphic Rock
Black Tourmaline
Schorl (NaFe2+3Al6(Si6O18)(BO3)3(OH)4)
mineral
Quartz with Iron Staining
Silicon Dioxide (SiO2) with Hematite/Limonite inclusions
mineral
Concretion (likely ironstone or carbonate)
Sedimentary concretion; exact mineral composition cannot be determined from the image
sedimentary
Quartz Geode Fragment
Silicon Dioxide (SiO2)
sedimentary
Fossilized Fish Vertebra
Vertebrata
fossil
Orange chalcedony (possibly carnelian)
Microcrystalline quartz, SiO₂; orange chalcedony is commonly called carnelian
mineral
Sandstone
Clastic sedimentary rock (primarily SiO2)
sedimentary
Orbicular jasper (often sold as leopard-skin jasper)
Silicified volcanic tuff/rhyolite; chiefly microcrystalline quartz and chalcedony (SiO₂), with iron oxides and altered volcanic minerals
sedimentary
Red Sandstone
Arenite (Iron-rich)
sedimentary
Red Jasper
Silicon Dioxide (SiO2) containing Iron Oxide inclusions
sedimentary
Banded Gneiss
Gneiss (Metamorphic high-grade rock)
metamorphic
Epidote-bearing Rock / Epidote Inclusion
Epidote (Ca2(Al, Fe)3(SiO4)3(OH)) in host rock
mineral
Pumice
Pumice (volcanic glass froth)
igneous
Sandstone (Ferruginous)
Arenite (with Iron Oxide)
sedimentary
Unknown dark mineral fragment
Indeterminate; possibly a dark silicate mineral or slag-like geological fragment
mineral
Basalt with Quartz/Calcite Veins
Aphanitic Mafic Igneous Rock (Hydrothermal Veined)
igneous
Serpentine-rich serpentinite
Serpentinite, chiefly lizardite–chrysotile–antigorite Mg₃Si₂O₅(OH)₄, possibly with calcite and talc
metamorphic
Coal (Bituminous / Anthracite)
Organic Sedimentary Rock (Carbonaceous Rock)
sedimentary
Sandstone (Pebble/Conglomerate fragment)
Sandstone (clastic sedimentary rock)
Sedimentary Rock
Limonite Stained Basalt
Hydrated Iron Oxide on Mafic Volcanic Rock (FeO(OH)·nH2O)
igneous
Chert (Flint)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
sedimentary
Sandstone
Sedimentary Clastic Rock
sedimentary
Diamond (or Diamond Simulant)
Carbon (C) if diamond, various if simulant (e.g., Cubic Zirconia ZrO2)
gemstone
Quartzite
Quartzite (SiO2)
metamorphic
Blue-green rough mineral specimen (identity uncertain)
Undetermined; the image is insufficient for a reliable mineral identification
mineral
Muscovite Mica
Muscovite (KAl2(AlSi3O10)(OH)2)
mineral
Limonite (Iron Ore)
Limonite (mixture of hydrated iron(III) oxide-hydroxides)
Mineral
Pegmatite
Igneous Pegmatite
igneous
Quartz-bearing geode or vuggy quartz specimen
Quartz, silicon dioxide (SiO₂), possibly with chalcedony and iron-oxide staining
mineral
Quartzite
Quartzite (SiO2)
metamorphic
Pumice or Scoria
Vesicular volcanic rock
Igneous
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Garnet in Matrix (likely Almandine Garnet)
Almandine (Fe3Al2(SiO4)3)
metamorphic
Pumice
Pumice (Vesicular volcanic glass / Rhyolite or Trachyte)
igneous