Sandstone (likely Arkosic or Quartzose)
Sandstone (SiO2 dominated)
sedimentary
Category
Not A Natural Rock (Man Made Composite)
Browse not a natural rock (man made composite) specimens identified by the Rock Identifier community.
Learn about Not A Natural Rock (Man Made Composite) in the encyclopedia
View all →
Hag Stone
Perforated Flint or Chert
sedimentary
Quartzite
Quartzite (SiO2)
metamorphic
Halite (Rock Salt)
Halite (NaCl)
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Petoskey Stone
Hexagonaria percarinata
sedimentary
Red Sandstone
Sandstone (lithic arenite / ferruginous sandstone)
sedimentary
Blue Dyed Agate Geode (Slice)
Silicon Dioxide (SiO2) - Chalcedony / Quartz
mineral
Smoky Quartz (Vein Quartz)
Quartz (Silicon Dioxide, SiO2)
mineral
Chalcedony (or a variety of Chalcedony, likely Agate or Jasper)
Chalcedony (SiO₂)
Mineral (or mineraloid if microcrystalline)
Dyed Agate
Silicon Dioxide (SiO2) with artificial pigment
mineral
Sandstone (Stream-rounded Cobble)
Arenite (composed primarily of SiO2, Silica)
sedimentary
Vesicular basalt (likely weathered lava rock)
Basalt; fine-grained mafic volcanic rock composed chiefly of plagioclase, pyroxene, and commonly olivine
igneous
Pumice
Pumice (a vesicular volcanic glass)
igneous
Chert (specifically Yellow/Brown Chert or Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Flagstone (Sandstone)
Sandstone (Silicon Dioxide with variations of Iron Oxide/Calcium Carbonate)
sedimentary
Granite
Granite (Felsic Plutonic Rock, consisting primarily of Quartz, Feldspar, and Mica)
Igneous
Aventurine
Aventurine Quartz (SiO2 with inclusions)
metamorphic
Rounded basalt cobble
Basalt, a fine-grained mafic volcanic rock composed mainly of plagioclase and pyroxene, commonly with olivine and iron oxides
igneous
Grooved Maun Ball (Maul/Hammerstone-like Concretion)
Calcareous/Ferruginous Concretion in Sandstone Matrix
sedimentary
Blue Agate Geode (Dyed)
Cryptocrystalline Quartz (SiO2)
mineral
Diorite
Diorite (Intermediate intrusive igneous rock)
igneous
Emerald in Matrix
Beryl (Be3Al2Si6O18)
mineral
Stainless Steel Spoon
Iron-Chromium Alloy (Fe + Cr + Ni)
mineral-based human-made alloy
Vuggy Limestone
Carbonate Sedimentary Rock with Vuggy Porosity (CaCO3)
sedimentary
Red Granite
Granite (Felsic intrusive igneous rock)
igneous
Granite Cobble/Pebble
Granite
Igneous
Iron-rich botryoidal limonite/goethite specimen
Limonite (amorphous hydrated iron oxides, chiefly goethite, α-FeO(OH))
mineral
Yellow quartz, possibly citrine
Quartz (SiO₂), yellow variety likely citrine; may also be iron-stained quartz
mineral
Basalt River Cobble
Basalt (Aphanitic Mafic Volcanic Rock)
igneous
Scoria (Lava Rock)
Scoria (vesicular basaltic rock)
igneous
Blue Sapphire
Corundum (Al2O3)
mineral
Ironstone Concretion / Limonite-stained Siltstone
Ironstone (primarily Limonite FeO(OH)·nH2O and Siltstone)
sedimentary
Metallic Ornament / Jewelry
N/A - This is an artificial object, not a geological specimen.
This appears to be a man-made metallic object, likely jewelry, not a natural rock, mineral, or geological specimen.
Likely tumbled basalt or dark volcanic rock
Basalt; chiefly plagioclase feldspar, pyroxene, and commonly olivine or iron oxides
igneous
Turquoise in Matrix
Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)
mineral
Lapis Lazuli
Lapis Lazuli (Complex rock consisting primarily of Lazurite (Na,Ca)8(AlSiO4)6(S,SO4,Cl)1-2)
metamorphic
Amethyst
Amethyst (Silicon Dioxide, SiO2 with Iron impurities)
mineral
Clear Quartz
Silicon dioxide (SiO2)
mineral
Pebble (likely Quartzite or Chert)
Clastic Sediment, potentially composed of SiO₂ (Quartz)
Mineral, Sediment
Gabbro Pebble (Polished Beach/River Stone)
Gabbro
igneous