Ironstone (likely Limonite or Goethite nodule)
Hydrothermally altered Ferric Hydroxide (FeO(OH)·nH2O)
Category
Browse organic (if resin) or synthetic (if glass); simulating sedimentary or metamorphic (for natural stones) specimens identified by the Rock Identifier community.
Ironstone (likely Limonite or Goethite nodule)
Hydrothermally altered Ferric Hydroxide (FeO(OH)·nH2O)
Petrified Wood (Jet or Coalified Wood appearance)
Silicified wood (principally SiO2) or Carbonized Wood
Quartz (Milky/Common)
Silicon Dioxide (SiO2)
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
Quartz Crystal Cluster
Silicon Dioxide (SiO2)
Mica Schist
Foliated Metamorphic Rock (Schist)
Jasper Shard / Chert
Silicon dioxide (SiO2)
Quartz Geode Fragment
Silicon Dioxide (SiO2)
Orange Calcite
Calcium Carbonate (CaCO3)
Botryoidal Quartz / Calcite Geode crust
Silicon Dioxide (SiO2) or Calcium Carbonate (CaCO3)
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Geode (unopened)
SiO2 - Chert-shelled concretion (mostly Quartz)
Bicolor Quartz (Milk Quartz with Slag or Dark Inclusions)
Silicon Dioxide (SiO2) with impurities
Sandstone
Quartz Arenite (a type of sandstone composed of more than 90% quartz)
Celestite (Celestine)
Strontium sulfate (SrSO4)
Ferruginous Sandstone
Clastic sedimentary rock (SiO2 with Fe2O3/FeO(OH) cement)
Milky Quartz with Iron Staining
Silicon Dioxide (SiO2)
Iron Ore (Hematite/Magnetite mixture)
Ferrous Oxide (Fe2O3 / Fe3O4)
Quartz (Iron-stained)
Silicon Dioxide (SiO2)
Pumice
Pumice (a highly vesicular volcanic glass)
Siltstone
Siltstone (primarily composed of SiO2 with various clay minerals)
Chert (specifically a Worked Flint/Knapped Flake)
Chert / Flint (Microcrystalline Quartz, SiO2)
Geode (Chert or Quartz Nodule)
Silicon Dioxide (SiO2)
Agate
Chalcedony (SiO2)
Basaltic Tuff / Volcanic Breccia
Pyroclastic Breccia / Lithic Tuff
Chert (Iron-stained or Jasperoid)
Microcrystalline Quartz (SiO2)
Almandine Garnet
Iron aluminum silicate (Fe3Al2(SiO4)3)
Chert / Flint
Silicon dioxide (SiO2)
Gastropod Fossil (Snail Steinkern)
Class Gastropoda fossil, composed of Calcium Carbonate (CaCO3)
Yellow Jasper
Silicon Dioxide (SiO2)
Sandstone Clast
Arenite (primarily SiO2)
White Quartz
Quartz (SiO2)
Peach Selenite / Orange Gypsum
Calcium Sulfate Dihydrate (CaSO4·2H2O)
Sandstone (Quartzose Sandstone)
Clastic Sedimentary Rock (primarily SiO2)
Silicon Carbide (Carborundum)
Silicon Carbide (SiC)
Greenstone
Greenschist / Greenstone (containing Chlorite, Epidote, Actinolite)
Yellow Calcite
Calcium Carbonate (CaCO3)
Yellow Quartzite Pebble
Quartzite (SiO2)
Coquina / Fossiliferous Limestone
Bioclastic Limestone (CaCO3)
Quartz / Common Agate
Silicon Dioxide (SiO2)
Gold Nugget
Native Gold (Au)
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)