Hematite
Iron(III) oxide (Fe2O3)
Category
Browse anthropogenic specimen (man made) specimens identified by the Rock Identifier community.
Hematite
Iron(III) oxide (Fe2O3)
Chert Nodules (with Gryphaea or Shell inclusions)
Microcrystalline Quartz (SiO2) with Calcitic inclusions
Chert / Flint (with Crinoid Stem Molds)
Microcrystalline Quartz (SiO2)
Gold Ore in Quartz
Auriferous Quartz (SiO2 with Au inclusions)
Granitic Quartz (with Feldspar inclusions)
Quartz (SiO2) with Potassium Feldspar (KAlSi3O8)
Amethyst (Agate/Chalcedony variety)
Silicon Dioxide (SiO2) with iron impurities
Jasper with Epidote (Unakite-related)
Epidotized Quartzite (composed of Quartz, Epidote, and Feldspar)
Quartz Geode Pebble
Silicon Dioxide (SiO2)
Sandstone (Quartz-rich)
Arenite (composed primarily of SiO2)
Green Fluorite (Beaded)
Fluorite (Calcium Fluoride, CaF2)
Granodiorite Pebble
Granodiorite
Blue Lace Agate
Silicon Dioxide (SiO₂), a variety of Chalcedony
Blue Lace Agate
Chalcedony (cryptocrystalline variety of Quartz), SiO2
Basalt
Basalt (Mafic igneous rock)
Basalt River Stone
Aphanitic Mafic Igneous Rock (primarily Plagioclase and Pyroxene)
Basalt (Beach Pebble)
Extrusive mafic igneous rock
Basalt Pebble
Extrusive mafic igneous rock
Sandstone
Arenite (SiO2 based)
Ironstone Concretion / Limonite-stained Siltstone
Ironstone (primarily Limonite FeO(OH)·nH2O and Siltstone)
Pyrite
Iron Sulfide (FeS2)
Vesicular Basalt (commonly mistaken for Slag)
Scoriaceous Basalt (composed primarily of Plagioclase Feldspar and Pyroxene)
Fossiliferous Limestone (Chertified Limestone)
Calcium Carbonate (CaCO3) often replaced by Microcrystalline Silica (SiO2)
Ferruginous Sandstone (Ironstone)
Arenite with Iron-Oxide Cement (FeO(OH)·nH2O / Fe2O3)
Quartz Pebble (Milky and Gray)
Quartz (Silicon Dioxide, SiO2)
Basalt with Magnetite
Crystalline Basalt (Primarily Plagioclase and Pyroxene) with Magnetite (Fe3O4)
Yellow Quartzite (River Pebble)
Quartzite (SiO2 with iron oxide impurities)
Quartz (Common Quartz Pebble)
Silicon Dioxide (SiO2)
Chert (Jasper/Common Opal mix)
Microcrystalline Quartz (SiO2)
Quartzite with inclusions
Metamorphic Rock (Mainly SiO2)
Chert (Jasper-bearing)
Microcrystalline silica (SiO2) with iron oxide inclusions
Sandstone Pebble
Arenite (primarily SiO2)
Dyed Quartzite
Metamorphosed Quartz (SiO2) with synthetic pigment
Chert (Iron-stained)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Rhyolite Pebble
Rhyolite
Banded Gneiss
Gneiss (complex metamorphic silicate rock)
Quartz Pebble
Silicon Dioxide (SiO2)
Gneiss
High-grade metamorphic rock (Gneiss)
Chert (Yellow Jasper variant)
Microcrystalline Quartz (SiO2)
Chert (Arrowhead/Tool variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Iron Slag
Iron Slag (Industrial Vitreous Material)
Quartz (Tumbled)
Silicon Dioxide (SiO2)
Banded Chert (River Cobble)
Microcrystalline Quartz (SiO2)