Gneiss
Gneiss
Category
Browse mineral on sedimentary rock specimens identified by the Rock Identifier community.
Gneiss
Gneiss
Chert (often called Flint when dark)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Concrete
Anthropogenic Sedimentary Rock (Hydrated Calcium Silicate)
Sandstone (likely Graywacke or Lithic Sandstone)
Arenite / Wacke (SiO2 based with lithic fragments)
Red Sandstone
Arenite (with Iron Oxide cement)
Gossan with Copper Carbonate (Chrysocolla/Malachite)
Ferruginous Oxide (Gossan) with Cu2CO3(OH)2 (Malachite) or (Cu,Al)2H2Si2O5(OH)4 (Chrysocolla)
Geode (Chert or Quartz Nodule)
Silicon Dioxide (SiO2)
Sandstone with Ironstone Banding
Clastic Sandstone (composed of Quartz with Hematite/Limonite bonding)
Chert Concretion (with typical hematite/limonite staining)
Sedimentary Concretion (SiO2 with FeO(OH)⋅nH2O)
Quartz
Quartz (SiO₂)
Chert (Nodule)
Chert (composition: SiO2)
Chert / Flint Conglomerate
Silicified Sedimentary Breccia (primarily SiO2)
Jasper
Silicon dioxide / Chalcedony (SiO2)
Green Aventurine (Green Quartzite)
Silicon Dioxide (SiO2) with inclusions of Fuchsite mica
Gneiss
Gneiss (High-grade Metamorphic Rock)
Gneiss
Gneiss
Banded Gneiss
Gneiss (complex metamorphic silicate rock)
Jasper
Silicon dioxide (SiO2) with impurities
Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
Jasper
Jasper / Silicon Dioxide (SiO₂)
Greenschist
Greenschist facies rock
Rough Quartz (or Quartzite pebble)
Silicon Dioxide (SiO2)
Hag Stone
Calcareous sedimentary rock (often Chert, Flint, or Limestone)
Boulder Opal
Precious Opal in Ironstone (Amorphous Hydrated Silica, SiO2·nH2O)
Sandstone Concretion
Moqui Marble / Iron-oxide Concretion (SiO2 with Hematite/Goethite)
Gneiss
Gneiss (High-grade metamorphic rock)
Agatized Chert / Chalcedony
Silicon Dioxide (SiO2)
Banded Gneiss
Gneiss (High-grade regional metamorphic rock)
Limonite stained Sandstone
Sedimentary rock with Goethite/Limonite (FeO(OH)·nH2O)
Greywacke with Quartz Veins
Lithic Sandstone (Greywacke) with SiO2 inclusions
Dendritic Agate (specifically Orange/Tumbled)
Silicon Dioxide (SiO2) with Oxide Inclusions
Amethyst Geode
Silicon Dioxide with trace inclusions of Iron (SiO2)
Banded Agate (Onyx variety)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Blue Calcite
Calcium Carbonate (CaCO3)
Carnelian (a variety of Chalcedony)
Cryptocrystalline Quartz (SiO2) with iron oxide inclusions
Blue Chalcedony
Silicon Dioxide (SiO2)
Agate (specifically Waterline or Onyx-type Agate)
Silicon Dioxide (SiO2) - variety Chalcedony
Yellow Chert (Jasper)
Silicon Dioxide (SiO2)
Druzy Quartz on Agate/Chert
Silicon Dioxide (SiO2)
Greywacke (River Slikkenstone)
Greywacke (Impure Sandstone)
Green Moss Agate
Silicon Dioxide (SiO2) with inclusions of hornblende or chlorite
Sandstone
Sandstone (principally SiO2)