Sandstone Concretion
Ferruginous Sandstone Concretion
Category
Browse igneous, sedimentary, metamorphic, mineral, gemstone, fossil, or meteorite specimens identified by the Rock Identifier community.
Sandstone Concretion
Ferruginous Sandstone Concretion
Sandstone Concretion
Clastic Sedimentary Concretion (typically Quartz/Silica with Iron Oxide)
Petrified Wood (Silicified Wood)
Silicified fossil wood (SiO2)
Quartz
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Quartz (Milky or Yellow/Citrine Quartz)
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Quartz (Milky/Crystalline fragment)
Silicon Dioxide (SiO2)
Ironstone Concretion
Siderite or Hematite-bonded Concretion
Quartz (Milky/Common)
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Ironstone concretion / Limonitic Sandstone
Goethite/Hematite Cemented Sandstone (Hydrated Iron Oxide)
Quartz
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Milky Quartz
Quartz (SiO2)
Likely polished basalt or iron-rich metamorphic rock
Basaltic rock, chiefly plagioclase and pyroxene; exact identification requires testing
Quartz
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Fossil shark tooth
Likely fossilized shark tooth, possibly Carcharhinus or Otodus species
White Quartz
Silicon Dioxide (SiO2)
White Quartz
Silicon Dioxide (SiO2)
Ironstone Concretion
Ironstone (Limonite/Goethite Concretion)
Blue Apatite
Calcium Fluorophosphate - Ca5(PO4)3F
Pallasite Meteorite
Pallasite (ST-class)
Magnetite (Iron Ore)
Magnetite (Fe3O4)
Quartz
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Tumbled dark quartzite or basalt pebble
Likely fine-grained basalt (plagioclase–pyroxene), though quartzite is possible from the image
White Quartz
Silicon Dioxide (SiO2)
Limestone Concretion (Botryoidal/Calcareous Nodules)
Calcium Carbonate Concretion (CaCO3)
Quartz (Milky/Clear variety)
Silicon Dioxide (SiO2)
Ferruginous Sandstone (Ironstone Nodules)
Ferruginous Sandstone with Limonite/Goethite coating (Fe2O3·H2O)
Quartz
Silicon Dioxide (SiO2)
Quartz (Pale Rose or Milky Variety)
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Weathered metallic-looking rock, possibly hematite-bearing ironstone
Hematite-rich ironstone; hematite Fe₂O₃, potentially with magnetite Fe₃O₄ and quartz
Quartz
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)