Amethyst
Silicon Dioxide (SiO2) with iron impurities
Category
Browse mineral, often found as a rock specimens identified by the Rock Identifier community.
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Red Garnet
Garnet Group (e.g., Pyrope, Almandine, Spessartine, Grossular, Andradite, Uvarovite)
Chert (Nodule)
Microcrystalline Quartz (SiO2)
Note: Item is not a geological specimen
Guitar Components (Steel, Nickel, Plastic, Wood)
Chert (Nodule)
Silicon Dioxide (SiO2)
Shale
Argillaceous Rock
Sandstone (lithic wacke)
Arenite / Lithic Wacke (mostly SiO2 with rock fragments)
Limonite (Iron Ore)
Hydrous Iron Oxide (goethite, lepidocrocite)
Quartz (River Pebble)
Silicon Dioxide (SiO2)
Sandstone (Glacial Cobble)
Arenite / Sedimentary Rock (primarily SiO2)
Chert (Quartzite-rich River Pebble)
Silicon Dioxide (SiO2)
Garnet-Bearing Schist
Almandine Garnet Micaceous Schist
Chert (Yellow Jasper/Quartzite Pebble)
Microcrystalline Silicon Dioxide (SiO2)
Amber Agate / Carnelian
Chalcedony (Silicon Dioxide, SiO2)
Granite with Epidote
Granite, containing quartz, feldspar, and epidote
Coquina / Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate - CaCO3)
Sandstone (Quartzose)
Arenite (primarily SiO2)
Unakite
Epidotized Granite
Banded Agate
Microcrystalline Quartz (SiO2) with impurities
Limonite (Iron Ore)
FeO(OH)·nH2O (Hydrous ferric oxide)
Chert (Flint)
Chert (Microcrystalline Quartz, SiO2)
Bauxite
Bauxite (Al2O3·nH2O)
Charoite
Charoite (K(Ca,Na)2Si4O10(OH,F)·H2O)
Gold
Gold (Native Au)
Greenstone
Greenschist / Meta-basalt
Shale
Shale (Lutite)
Chert (Flint)
Silicon Dioxide (SiO2)
Quartz Vein Rock
Quartz (Silicon Dioxide, SiO2)
Azurite and Malachite on Matrix
Cu3(CO3)2(OH)2 (Azurite) and Cu2CO3(OH)2 (Malachite)
Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Agate
Silicon Dioxide (SiO2) - Banded Chalcedony
Sandstone (Ferruginous)
Arenite with Iron Oxide (Limonite/Hematite) coating
Sandstone Concretion
Sedimentary concretion
Chert (Nodule)
Crystalline Silicon Dioxide (SiO2)
Chert (Flint Nodular Variety)
Microcrystalline Quartz (SiO2)
Gold Nugget
Native Gold (Au)
Chert
Microcrystalline Quartz (SiO2)
Yellow Quartz (Citrine/Yellow Jasper)
Silicon Dioxide (SiO2)
Jasper (likely Brecciated or Multi-colored)
Jasper (SiO2)
Banded Sandstone
Arenite (with iron oxide banding)
Bauxite (Laterite Clay)
Bauxite (mixture of Hydrous Aluminum Oxides: Gibbsite Al(OH)3, Boehmite and Diaspore AlO(OH))