Gneiss
Gneiss (High-grade Metamorphic Rock)
Category
Browse sedimentary rock (specifically a chemical sedimentary rock, or a chert if considered purely mineral aggregate) specimens identified by the Rock Identifier community.
Gneiss
Gneiss (High-grade Metamorphic Rock)
Quartz (Microcrystalline variety)
Silicon Dioxide (SiO2)
Clear Quartz
Silicon Dioxide (SiO2)
Caliche (also known as hardpan, calcrete, kankar)
Primarily composed of calcium carbonate (CaCO₃), often mixed with other minerals like quartz, clay minerals, and iron oxides.
Sandstone
Arenite (primarily SiO2)
Jasper with Quartz Veining
Silicon Dioxide (SiO2) - Opaque cryptocrystalline variety of Quartz
Sandstone (likely Graywacke or Arkose variant)
Clastic Sedimentary Rock (Lithic Sandstone)
Quartz
Silicon dioxide (SiO2)
Sandstone
Clastic sedimentary rock (primarily SiO2)
Druzy Chalcedony (Agate Geode)
Silica (SiO2) - Cryptocrystalline Quartz with druzy macrocrystalline quartz
Sandstone
Arenite
Carnelian
Carnelian (SiO2 with Iron Oxide impurities)
Sandstone (likely Quartzose type)
Clastic sedimentary rock (primarily SiO2)
Sandstone (Ferruginous)
Arenite (SiO2 with Fe2O3 inclusions)
Sandstone
Arenite (SiO2 based)
Sandstone (likely Arkose)
Arenite (composed mainly of SiO2 with Feldspar)
Sandstone (Pebble)
Arenite (SiO2 based)
Clear Quartz Cluster
Silicon Dioxide (SiO2)
Conglomerate
Conglomerate
Shale
Fissile mudstone (primarily clay minerals and silt-sized quartz)
Concretion with Quartz Veining
Septarian Concretion (CaCO3 / SiO2)
Sandstone
Arenite (SiO2 based)
Sandstone
Arenite (composed primarily of SiO2)
Sandstone
Arenite (primarily SiO2)
Biotite Schist
Biotite Schist
Sandstone
Arenite (primarily composed of SiO2 - Silicon Dioxide)
Sandstone
Arenite (primarily SiO2 - Silicon Dioxide)
Sandstone
Arenite (SiO2 based)
Sandstone (likely Ferruginous)
Sandstone (SiO2 with iron oxides)
Fossilized Dinosaur Skull (Tyrannosaurus rex)
Tyrannosaurus rex (permineralized fossil), rich in Hydroxylapatite/Silica
Ferruginous Sandstone
Arenite with Iron-Oxide cement (primarily Fe2O3 • nH2O)
Ferruginous Sandstone with Quartz Inclusions
Clastic Sedimentary Rock (Iron-rich Sandstone)
Limonite (Iron Ore)
FeO(OH)·nH2O
Sandstone (Ferruginous)
Arenite (SiO2 with Iron Oxide impurities)
Banded Chert (or Banded Jasper)
Silicon Dioxide (SiO2) with Iron Oxide impurities (Hematite/Goethite)
Quartz Geode in Sedimentary Matrix
Silicon Dioxide (SiO2) within a limestone/dolostone host
Quartz Geode Fragment
Silicon Dioxide (SiO2)
Sandstone Concretion
Clastic Sedimentary Rock - Quartz Arenite / Sandstone
Yellow Jasper
Silicon Dioxide (SiO2) with iron hydroxides (Goethite/Limonite)
Fancy Jasper (Multicolor Agate/Jasper)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Quartz (Druzy/Macro-crystalline)
Silicon Dioxide (SiO2)
Leopard Skin Jasper
Jasper (Silicon Dioxide with impurities), SiO2