Limonite/Ironstone
Limonite (FeO(OH)·nH2O)
mineral
Category
Mineral (Biogenic)
Browse mineral (biogenic) specimens identified by the Rock Identifier community.
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Greenstone
Metabasalt / Chlorite Schist
metamorphic
Gneiss
Gneiss
metamorphic
Gneiss (specifically Granitic Gneiss)
Gneiss (composed primarily of Quartz, Feldspar, and Biotite/Amphibole)
metamorphic
Granite
Granite (Felsic Plutonic Rock)
igneous
Coarse-grained Granite
Granitoid (KAlSi3O8 + SiO2 + NaAlSi3O8)
igneous
Gneiss
Gneiss (High-grade metamorphic rock composed primarily of Quartz, Feldspar, and various Micas)
metamorphic
Sandstone
Arenite
sedimentary
Sandstone (with banding)
Arenite (primarily SiO2)
sedimentary
Sandstone (Picture Sandstone)
Arenite (primarily SiO2)
sedimentary
Native Copper (Penny specimen)
Native Copper (Cu)
mineral
Cubic Zirconia (Faceted)
Zirconium dioxide (ZrO2)
mineral
Sandstone
Arenite (SiO2 dominant)
sedimentary
Sandstone (Banded)
Clastic Sedimentary Rock (primarily SiO2)
sedimentary
Limonite (Iron Ore)
Limonite (Iron oxide-hydroxide mixture, FeO(OH)·nH2O)
mineral
Sandstone
Clastic sedimentary rock (primarily SiO2)
sedimentary
Not a geological specimen
N/A (man-made object)
N/A
Nickel
Nickel (Ni)
mineral
Quartz / Common Opal Transition
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Gneiss
Gneiss
metamorphic
Gneiss (specifically a Granitic Gneiss)
Gneiss (typically composed of Quartz, Feldspar, and Mica/Amphiboles)
metamorphic
Banded Gneiss
Gneiss (Metamorphic high-grade, predominantly SiO2, Al2O3, K2O, Na2O)
metamorphic
Diorite
Plutonic Igneous Rock (NaAlSi3O8, CaAl2Si2O8)
igneous
Granite
Granite (a common rock type, not a single mineral; composed primarily of Quartz, Feldspar (Orthoclase and Plagioclase), and Mica (Biotite and/or Muscovite) and/or Amphibole)
Igneous
Granitic Pegmatite
Pegmatite containing Quartz, Feldspar, and Muscovite mica
igneous
Greenstone
Greenschist (metamorphosed mafic igneous rock)
metamorphic
River Rock / Stream Pebble
Fluvial Clast / Rounded Sedimentary Particle
Sedimentary Rock (possibly composed of various minerals)
White Quartz with Black Tourmaline
Silicon Dioxide (SiO2) with Schorl (NaFe2+3Al6(Si6O18)(BO3)3(OH)3OH)
mineral
Bauxite
Bauxite (Al2O3·nH2O)
sedimentary
Quartz (with probable host rock)
Silicon Dioxide (SiO2)
mineral
Chert (specifically Flint or Jasper variant)
Microcrystalline Quartz (SiO2)
sedimentary
Olivine in Basalt (Peridotite Xenolith)
Forsterite-rich Olivine (Mg2SiO4) in Aphanitic Basalt
igneous
Bauxite
Bauxite (Al2O3·nH2O)
sedimentary
Limonite-stained Quartz
Silicon Dioxide (SiO2) with Iron Oxide/Hydroxide (FeO(OH)·nH2O) staining
mineral
Banded Chert
Microcrystalline Quartz (SiO2)
sedimentary
Lapis Lazuli
Lapis Lazuli (A metamorphic rock primarily composed of Lazurite: (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)
metamorphic
Limonite
Limonite (FeOO·nH2O)
mineral
Gossanous Sandstone (likely Terrestrial)
Arenite with Iron-Oxide inclusions
sedimentary
Quartz Geode (with possible Manganese or Goethite coating)
Silicon Dioxide (SiO2)
mineral
Eclogite
Eclogite (Omphacite + Pyrope)
metamorphic
Pyrite
Iron Sulfide (FeS2)
mineral