Biotite Mica
Biotite (K(Mg,Fe)3AlSi3O10(OH,F)2)
mineral
Category
Sedimentary Rock (Possibly Composed Of Various Minerals)
Browse sedimentary rock (possibly composed of various minerals) specimens identified by the Rock Identifier community.
Gneiss
Gneiss (High-grade regional metamorphic rock)
Metamorphic
Chert / Flint Nodules in Limestone
Silicon Dioxide (SiO2) within Calcium Carbonate (CaCO3)
sedimentary
Sandstone (with Iron Staining)
Clastic Sedimentary Rock (primarily SiO2)
sedimentary
Ironstone Concretion (Moqui Marble variety)
Ferruginous Sandstone Concretion
sedimentary
African Turquoise
African Turquoise (a trade name for Jasper, a variety of Chalcedony: SiO2)
sedimentary
White Chalcedony (likely Common Opal or Milky Quartz)
Silicon Dioxide (SiO2)
mineral
Limonite (Iron-rich Siltstone / Sandstone base)
Hydrous ferric oxide mixture (FeO(OH)·nH2O)
sedimentary
Turquoise
Hydrated phosphate of copper and aluminum, CuAl6(PO4)4(OH)8·4H2O
mineral
Dyed Agate Geode (Pink/Magenta)
Silicon Dioxide (SiO2) - variety of Chalcedony/Quartz
mineral
Geode with Quartz Crystal Cavity
Silicon Dioxide (SiO2) in Calcareous/Siliceous Matrix
sedimentary
Epidote
Epidote ({Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH))
mineral
Granite
Phaneritic Intrusive Igneous Rock (primarily composed of SiO2, Al2O3, K2O, Na2O)
igneous
Banded Gneiss (River Rock/Pebble)
Gneiss (specifically a banded variety often found as a river rock)
Metamorphic Rock
Glauconitic Sandstone (Greensand)
Glauconitic Quartz Arenite (containing Glauconite, (K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2)
sedimentary
Granite
Granite
igneous
Limonite (Iron Ore)
Limonite; FeO(OH)·nH2O
mineral
Conglomerate
Conglomerate (clastic sedimentary rock)
sedimentary
Picture Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Chert (Yellow Jasper/Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Almandine Garnet in Schist
Almandine Garnet (Fe3Al2(SiO4)3) in Mica Schist
metamorphic
Granite
Granite (Phaneritic Acidic Igneous Rock)
igneous
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
mineral
Gneiss with Quartz Vein
Gneiss containing Quartz (SiO2) filler
metamorphic
Gneiss
Gneiss (High-grade Metamorphic Rock)
metamorphic
Moqui Marble (Shaman Stone)
Iron Oxide Concretion (composed primarily of Quartz sand with Hematite/Goethite shell)
sedimentary
Sandstone
Arenite
sedimentary
Sandstone (Ferruginous)
Arenite (primarily SiO2 with Fe2O3 staining)
sedimentary
Quartz Geode
Silicon Dioxide (SiO2)
sedimentary
Sandstone (Ferruginous)
Arenite with Iron Oxides
sedimentary
Sandstone (River Cobble)
Clastic Sedimentary Rock (primarily Quartz with Feldspar)
sedimentary
Sandstone (Ferruginous)
Arenite with Iron oxide staining (SiO2 with Fe2O3)
sedimentary
Amazonite
KAlSi3O8 (Potassium Aluminum Silicate) - a variety of Microcline Feldspar
mineral
Gneiss
Gneissic Metamorphic Rock
metamorphic
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
mineral
Basalt with Vesicular Texture
Extrusive Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)
igneous
Conglomerate
Conglomerate (Clastic Sedimentary Rock)
sedimentary
Ferruginous Sandstone (with possible Epidote/Chlorite coloring)
Sandstone (SiO2 dominated with Fe2O3 staining)
sedimentary
Yellow Jasper (Iron-stained Quartz)
Jasper (Silicon Dioxide, SiO2 plus iron oxide impurities)
sedimentary
Basalt
Extrusive mafic igneous rock
igneous
Petrified Wood
Silicified wood, primarily composed of Quartz (SiO2)
Mineral, often found in sedimentary deposits
Red Jasper (Brecciated Jasper)
SiO2 (Silicon Dioxide) with Ferric Iron inclusions
sedimentary