Gneiss
Gneiss
Category
Browse sedimentary (with some aspects of mineral replacement) specimens identified by the Rock Identifier community.
Gneiss
Gneiss
Banded Sandstone (Liesegang Rings)
Arenite with Liesegang rings (SiO2/Fe2O3)
Fossil Seashell
Invertebrate fossil (Bivalvia)
River Stone (Granitic Gneiss)
Foliated Granitic Gneiss
Gneiss
Gneiss
Fairy Stone (Menilite Concretion)
Carbonate-rich concretion (often Siderite or Calcite in Clay)
Limonite / Goethite Ironstone
FeO(OH)·nH2O (Hydrous iron oxide)
Chert (with Quartz Veining)
Microcrystalline Quartz (SiO2)
Gneiss (specifically a Granitic Gneiss specimen)
Gneiss (high-grade metamorphic rock primarily composed of Quartz, Feldspar, and Biotite/Amphibole)
Gneiss
Gneiss
Gneiss
Gneiss (High-grade regional metamorphic rock)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Opal
Hydrated Silica (SiO2·nH2O)
Shale fragment
Shale (Laminated Mudstone)
Gneiss
Gneiss
Chert / Flint Nodule
Microcrystalline quartz (SiO2)
Chert / Flint (Arrowhead Artifact)
Microcrystalline quartz (SiO2)
Flint / Chert Pebble
Microcrystalline Quartz (SiO2)
Flint
Cryptocrystalline quartz (SiO2)
Flint / Chert (Fossiliferous)
Silicon dioxide (SiO2) with microcrystalline quartz
Red Sandstone (Arkose)
Clastic Sedimentary Rock (Lithic Arkose)
Gneiss
High-grade foliated metamorphic rock
Gneiss
Gneiss (High-grade metamorphic rock)
Red Jasper
Silicon Dioxide (SiO2) mixture
Granitic Gneiss
Gneiss (High-grade metamorphic rock)
Quartz Geode with Chalcedony
Crystalline Silicon Dioxide (SiO2)
Quartz Geode
Silicon Dioxide (SiO2)
Quartz Geode
Silicon Dioxide (SiO2)
Iron-Oxide Concretion (Moqui Marble)
Goethite/Hematite Concretion (Fe2O3 / FeO(OH))
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Gneiss
Gneiss (High-grade Metamorphic Rock)
Shale with Pyrite
Clastic sedimentary rock containing Iron Disulfide (FeS2)
Chalcedony Geode / Agate Nodule
Cryptocrystalline Quartz (SiO2)
Gneiss
Gneiss (High-grade metamorphic rock)
Unidentifiable Specimen
Undetermined
Red Sandstone
Sandstone (Iron Oxide Rich)
Moqui Marble (Iron Concretion)
Hematite-Goethite Concretion
Sandstone
Arenite (SiO2 secondary)
Fossilized Echinoid
Echinoidea (likely of the order Echinoidea)
Flint / Chert
Microcrystalline quartz (SiO2)
Chert (Jasper)
Microcrystalline Quartz (SiO2)
Chert (Pebble)
Microcrystalline Quartz (SiO2)