Banded gneiss (likely amphibolite-bearing gneiss)
Gneiss; quartz–feldspar–mica/amphibole aggregate
Category
Browse sedimentary or metamorphic (low grade) specimens identified by the Rock Identifier community.
Banded gneiss (likely amphibolite-bearing gneiss)
Gneiss; quartz–feldspar–mica/amphibole aggregate
Weathered limestone
Calcite-rich limestone (CaCO₃), possibly fossiliferous or dolomitic
Chert (Common Opal variant)
Silicon Dioxide (SiO2)
Ferruginous Conglomerate
Conglomerate with Iron-Oxide Matrix (SiO2 + Fe2O3/FeO(OH))
Ironstone (likely Ferruginous Siltstone/Sandstone)
Ferruginous sedimentary rock (FeOx-rich clastic)
Ironstone Concretion
Siderite or Hematite-bonded Concretion
Ironstone Concretion (Iron-rich Mudstone)
Siderite / Geothite concretion (FeCO3 / FeO(OH))
Banded Gneiss
Gneiss (High-grade Metamorphic Rock)
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
Anthracite Coal
Anthracite (Metamorphosed Carbon)
Green Calcite
Calcium Carbonate (CaCO3)
Gneiss
Gneiss (High-grade Metamorphic Rock)
Gneiss
High-grade foliated metamorphic rock
Gneiss
Gneiss (High-grade metamorphic rock)
Gneiss
Gneiss (High-grade metamorphic rock)
Banded Gneiss
Gneiss (High-grade metamorphic rock)
Pyrite
Iron Sulfide (FeS2)
Milky Quartz
Silicon Dioxide (SiO2)
Graphite
Graphite (Carbon, C)
Biotite Schist
Biotite-rich Schist
Pyrite in Matrix (Fool's Gold)
Iron Sulfide (FeS2)
Gneiss (Metamorphic Pebble)
Metamorphic Rock (Quartz-Feldspar-Biotite Gneiss)
Pyritic Gneiss (with Garnet)
Gneiss containing Pyrite (FeS2) and Almandine Garnet (Fe3Al2(SiO4)3)
Milky Quartz
Silicon Dioxide (SiO2)
Banded Gneiss
Gneiss (High-grade regional metamorphic rock)
Calcite
Calcium Carbonate (CaCO3)
Quartz Vein in Host Rock (Likely Slate or Shale)
Hydrothermal Quartz (SiO2) in Pelitic host rock
Red Jasper
Jasper (Silicon Dioxide, SiO2)
Quartz with Mica inclusions (likely Schist or Gneiss host)
Silicon Dioxide (SiO2) with Phyllosilicates (KAl2(AlSi3O10)(OH)2)
Unidentifiable Rock Fragment
Gneiss
Gneiss (Foliated Metamorphic Rock)
Banded Gneiss
Gneiss (Metamorphic silicate rock)
Serpentine
Antigorite, Lizardite, or Chrysotile; Mg3Si2O5(OH)4
Banded Gneiss
Gneiss (High-grade metamorphic rock)
Gneiss
Gneiss (High-grade metamorphic rock)
Gneiss
Gneiss (High-grade metamorphic rock)
Granite Gneiss
Gneiss (High-grade metamorphic rock)
Gneiss
High-grade metamorphic rock (Gneiss)
Gneiss
Gneiss (High-grade Metamorphic Rock)
Ironstone Concretion / Limonite-stained Siltstone
Ironstone (primarily Limonite FeO(OH)·nH2O and Siltstone)
Granite Gneiss
Gneiss (High-grade regional metamorphic rock)
Banded Gneiss
Gneiss (High-grade Regional Metamorphic Rock)