Chalcedony (Moonstone-like Agate)
Silicon Dioxide (SiO₂)
Category
Browse metamorphic or sedimentary depending on local grade specimens identified by the Rock Identifier community.
Chalcedony (Moonstone-like Agate)
Silicon Dioxide (SiO₂)
Jasper
Silicon Dioxide (SiO2) with impurities
Sandstone with Quartz Veining
Arenite with hydrothermal quartz (SiO2)
Chert
Silicon dioxide (SiO2)
Sandstone (Quartzose Sandstone)
Clastic Terrigenous Sedimentary Rock (primarily SiO2)
Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Red Ochre (Hematite-rich Clay)
Limonitic/Hematitic Claystone (Fe2O3 with clay minerals)
Quartz (Pale Rose or Milky Variety)
Silicon Dioxide (SiO2)
Quartz (Milky/Common)
Silicon Dioxide (SiO2)
Magnetite (Lodestone variety)
Magnetite (Fe3O4)
Quartz (Milky Variant)
Silicon Dioxide (SiO2)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Green Jasper
Silicon Dioxide (SiO2) with impurities
Chert (varietal: Jasper or Flint)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
Ironstone Concretion (Moqui Marble Type)
Goethite/Hematite-cemented Sandstone Concretion
Green Jasper
Jasper (variety of Microcrystalline Quartz, SiO2)
Banded Chert (Flint)
Cryptocrystalline Quartz (SiO2)
Conglomerate
Conglomerate (Sedimentary Clastic Rock)
Geode (Unopened)
Siliceous Geode (SiO2)
Gypsum (Wallboard/Drywall)
Calcium Sulfate Dihydrate (CaSO4·2H2O)
Montana Moss Agate
Chalcedony (SiO2) with Manganese/Iron oxide inclusions
Conglomerate
Conglomerate (clastic sedimentary rock)
Beach Pebble (Chert/Quartzite)
Microcrystalline Quartz (SiO2)
Optical Calcite (Iceland Spar)
Calcium Carbonate (CaCO3)
Ironstone Concretion (Limonite/Goethite)
Ferruginous Sandstone / Ironstone (FeO(OH)·nH2O)
Bauxite
Bauxite (Al2O3·nH2O)
Ironstone Concretion
Siderite or Limonite Concretion
Ferruginous Sandstone (Gozzan)
Iron-rich clastic sedimentary rock with Limonite/Goethite
Limonite (Ironstone Concretion)
Limonite (Hydrous ferric oxide mixture, FeO(OH)·nH2O)
Lapis Lazuli
Lapis Lazuli (Complex aggregate of Lazurite, Calcite, and Pyrite)
Nephrite Jade
Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2)
Ruby (Pink to Red Corundum)
Al2O3 (Corundum with Chromium impurities)
Conglomerate
Clastic Sedimentary Rock (Conglomerate)
Limonite (Iron Ore)
Limonite (FeO(OH)·nH2O)
Garnet (Almandine or Spessartine likely)
Garnet Group Minerals (e.g., Almandine Fe3Al2(SiO4)3, Pyrope Mg3Al2(SiO4)3, Spessartine Mn3Al2(SiO4)3)
Citrine (Quartz variant)
SiO2 (Silicon Dioxide)
Chert (and Chalcedony/Agate mixture)
Microcrystalline Quartz (SiO2)
Polygenetic Breccia
Clastic Breccia (containing lithic fragments in a fine-grained matrix)
Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
Conglomerate
Conglomerate (Detrital Sedimentary Rock)
Sandstone (Pebble)
Sandstone (arenite, arkose, wacke depending on composition)