Amethyst Quartz
Silicon Dioxide (SiO2) with iron impurities
Category
Browse sedimentary (formed from silica deposits) specimens identified by the Rock Identifier community.
Amethyst Quartz
Silicon Dioxide (SiO2) with iron impurities
Orange Calcite (Carved as a Horned Skull)
Calcium Carbonate (CaCO3)
Limonite (Ironstone Concretion)
Limonite (Hydrous ferric oxide mixture, FeO(OH)·nH2O)
Milky Quartz
Silicon Dioxide (SiO2)
Amber
Succinite (Resin C10H16O)
Green Calcite
Calcite (Calcium Carbonate, CaCO3)
Fluorite
Calcium Fluoride (CaF2)
River Quartzite / Tumble-Polished Quartz
Quartzite (SiO2)
Native Copper (Penny specimen)
Native Copper (Cu)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Chert (Chert Nodule with Chalky Cortex)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Conglomerate (or Breccia)
Clastic Sedimentary Rock
Sandstone (with carbonaceous plant fragments)
Arenite (composed primarily of SiO2)
Common Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Geode (Unopened)
Silica-lined Vug (primarily SiO2)
Howlite
Calcium borosilicate hydroxide (Ca2B5SiO9(OH)5)
Conglomerate
Clastic sedimentary rock (Conglomerate)
Tree Agate
Silica (SiO2) with Chlorite inclusions
Fossiliferous Limestone (Coquina / Shell Limestone)
Biogenic Limestone (Calcium Carbonate, CaCO3)
Ferruginous Sandstone
Arenite with Hematite/Limonite cement (SiO2 + Fe2O3)
Clear Quartz
Silicon Dioxide (SiO2)
Fluorite (translucent octahedral crystal)
Calcium fluoride (CaF2)
Shiva Lingam
Cryptocrystalline Quartz (Jasproid/Sandstone) with Iron Oxide (Fe2O3)
Clear Quartz Crystal
Silicon Dioxide (SiO2)
Sandstone (likely Arkose or Quartz Sandstone)
Arenite (SiO2 + varied clasts)
Belemnoit Fossil (Sea Squid Fossil)
Belemnitida (Order within Cephalopoda)
Yellow Quartz Pebble
Silicon Dioxide (SiO2)
Ironstone (with Limonite/Goethite)
Ferruginous Sedimentary Rock (contains Limonite FeO(OH)·nH2O and Hematite Fe2O3)
Coquina
Bioclastic Limestone (Calcium Carbonate, CaCO3)
Coquina
Bioclastic Limestone (composed primarily of CaCO3)
Sandstone
Arenite (SiO2 based)
Amethyst
SiO2 (Silicon Dioxide with Iron impurities)
Bauxite
Bauxite (Mixture of Hydrous Aluminum Oxides)
Red Jasper
Silicon Dioxide (SiO2) with Hematite (Fe2O3) impurities
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Pink Amethyst Geode
Silicon Dioxide (SiO2) with Hematite/Iron impurities
Aragonite Star Cluster
Aragonite (Calcium Carbonate - CaCO3)
Black Sapphire
Corundum (Al2O3 with inclusions of hematite or ilmenite)
Shiva Lingam
Cryptocrystalline Quartz (Jasproid/Jasper)
Limestone
Calcium Carbonate (CaCO3)
White Quartz Pebbles
Quartz (Silicon Dioxide, SiO2)
Oyster Shell (Aragonite/Calcite)
Calcium Carbonate (CaCO3)