River Rock (Greywacke/Sandstone)
Lithic Wacke
Category
Browse mineral (or mineraloid if microcrystalline) specimens identified by the Rock Identifier community.
River Rock (Greywacke/Sandstone)
Lithic Wacke
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxide inclusions)
Sandstone (Quartz-rich)
Arenite (SiO2 based)
Sandstone (Ferruginous)
Clastic sedimentary rock (primarily SiO2 with Fe2O3 staining)
Dyed Alum or Dyed Quartz (Ornamental Crystal)
Silicon Dioxide (SiO2) or Potassium Alum [KAl(SO4)2·12H2O]
Hematite
Iron(III) oxide (Fe2O3)
Ferruginous Sandstone
Sandstone with iron oxide (Hematite/Limonite) cement
Sandstone (Quartzose)
Arenite (primarily SiO2)
Sandstone (Ferruginous)
Arenite (primarily SiO2 with Fe2O3 staining)
Gold Nugget
Native Gold (Au)
Quartz Geode (with Calcite influence)
Silicon Dioxide (SiO2) with possible Calcium Carbonate (CaCO3)
Sandstone
Arenite (primarily Quartz, SiO2)
Sandstone (likely Quartzose)
Sandstone (Principally SiO2)
Hematite
Ferric oxide (Fe2O3)
Sandstone (Quartzite-rich Pebble)
Arenite (primarily SiO2)
Chalcedony (Agate Pebble)
Silicon Dioxide (SiO2)
Quartz (Milky/Crystalline variety)
Silicon Dioxide (SiO2)
Sandstone (Ferruginous)
Arenite (primarily SiO2 with Fe2O3 staining)
Olivine Basalt
Mafic Volcanic Rock (rich in (Mg, Fe)2SiO4)
Quartz Vein in Sedimentary Rock
Silicon Dioxide (SiO2) with host Chert or Limestone
Quartz (Clear Quartz/Rock Crystal)
Silicon Dioxide (SiO2)
Chrysocolla in Matrix
Hydrated copper phyllosilicate mineral (Cu,Al)2H2Si2O5(OH)4·nH2O
Basalt with Jasper Veining
Basaltic Rock with Cryptocrystalline Quartz (SiO2)
Ferruginous Quartz
Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions
Sandstone (likely Quartzose Sandstone)
Arenite (SiO2 principal composition)
Rough Corundum (Sapphire/Ruby mixture)
Corundum (Aluminum Oxide, Al2O3)
Aquamarine
Beryl (Be3Al2Si6O18 with iron impurities)
Milky Quartz (with Chlorite/Mineral Inclusions)
Silicon Dioxide (SiO2)
Amethyst
Silicon dioxide / Violet Quartz (SiO2)
Agate (Chert/Chalcedony)
Silicon Dioxide (SiO2)
Sandstone
Arenite (SiO2 primarily)
Sandstone (Ferruginous)
Arenite with Iron Oxide matrix
Sandstone
Arenite (composed primarily of SiO2)
Tiger's Eye
Pseudomorph of Macrocrystalline Quartz after Crocidolite (SiO2)
Ruby (Corundum)
Corundum (Aluminum Oxide) with chromium trace elements, Al2O3
Quartz Geode (Cracked)
Silicon Dioxide (SiO2)
Quartz with Limonite Staining
Silicon Dioxide (SiO2) with Hydrated Iron Oxide (FeO(OH)·nH2O)
Sandstone (with Lichen)
Arenite (composed primarily of SiO2)
Smoky Quartz (Ferruginous Quartz)
Quartz (Silicon Dioxide, SiO2)
Basalt with Calcite Veins
Aphanitic mafic volcanic rock with CaCO3 inclusions
Geode (Unopened)
Silica-rich concretion (SiO2)
Amethyst
Amethyst (Silicon Dioxide - SiO2)