Gneiss
Gneiss
Category
Browse sedimentary (with some aspects of mineral replacement) specimens identified by the Rock Identifier community.
Gneiss
Gneiss
Chert (Chert / Flint)
Silicon Dioxide (SiO2)
Red Jasper
Silicon Dioxide (SiO2) with Hematite impurities
Chert (Jasper variation)
Microcrystalline Quartz (SiO2)
Chert (Nodular Chert)
Silicon Dioxide (SiO2)
Jasper
Silicon dioxide (SiO2)
Sandstone (Ferruginous Concretion)
Ferruginous Sandstone Concretion / SiO2 with Fe2O3 cement
Quartz Veinated Sandstone or Siltstone
Silicon Dioxide (SiO2) within a clastic sedimentary matrix
Granitic Gneiss
Gneiss (containing Potassium Feldspar and Quartz)
Concretion
Septarian concretion (likely containing Calcite or Siderite)
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
Gneiss (Banded Gneiss)
Gneiss
Gneiss
Gneiss (High-grade metamorphic rock)
Ironstone Concretion
Limonitic/Hematitic Concretion
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
Quartz (Milky or Rough Variety)
Silicon Dioxide (SiO2)
Pyrite
Pyrite (Iron Disulfide), FeS2
Ferruginous Sandstone
Sandstone with Iron Oxide (Limonite/Goethite)
Moqui Marble (Moqui Ball)
Ironstone Concretion (Goethite/Hematite cemented Sandstone)
Quartz Geode
Silicon Dioxide (SiO2)
Gneiss
Gneiss
Yellow Chert or Jasper
Microcrystalline Quartz (SiO2)
Chert (Nodule)
Silicon Dioxide (SiO2)
Chert (containing Orbicular/Agate patterns)
Microcrystalline Quartz (SiO2)
Chert (Jasper variety)
Silicon Dioxide (SiO2)
Ammonite Fossil
Ammonoidea (primarily composed of Calcite, CaCO3, or Pyrite)
Yellow Jasper / Chert
Jasper (Silica/Quartz) - SiO2
Chert
Siliceous sedimentary rock (predominantly microcrystalline quartz, SiO2)
Red Jasper (Skull Carving)
Jasper, a cryptocrystalline variety of Quartz (SiO2)
Banded Gneiss with Quartz Vein
Foliated Metamorphic Rock (Gneiss)
Sandstone (Ferruginous)
Clastic Sedimentary Rock (SiO2 with Fe2O3/FeOOH cement)
Raw Green Jasper
Silicon Dioxide (SiO2) with iron silicate inclusions
Banded Gneiss
Gneiss (High-grade Metamorphic Rock)
Flint Nodule
Microcrystalline Quartz (SiO2)
Chert (Flint) Nodule
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Rhodonite
Rhodonite (Manganese Iron Magnesium Calcium Silicate - (Mn,Fe,Mg,Ca)SiO3)
Petrified Wood
Silicified Wood (SiO2)
Muscovite Mica (with Schist)
Muscovite - KAl2(AlSi3O10)(OH)2
Petrified Wood
Silicified Wood (primarily SiO2)
Red Jasper
Jasper (Silicon Dioxide, SiO2 with iron oxide impurities)
Chert (often called Flint or Jasper)
Silicon Dioxide (SiO2)
Pyrite
Iron Sulfide (FeS2)