Iron-stained Quartz
Silicon Dioxide with Iron Oxide (SiO2 + Fe2O3/FeO(OH))
Category
Browse organic gemstone (not a rock or mineral) specimens identified by the Rock Identifier community.
Iron-stained Quartz
Silicon Dioxide with Iron Oxide (SiO2 + Fe2O3/FeO(OH))
Quartz Druzy on Geode Fragment
Silicon Dioxide (SiO2)
Diorite
Diorite (Intermediate intrusive igneous rock)
Quartz (Vein Quartz)
Silicon Dioxide (SiO2)
Granite (with alteration)
Granite (Felsic intrusive igneous rock)
Sandstone (likely Arkosic or Quartzose)
Arenite (SiO2 based with mineral inclusions)
Moonstone
Orthoclase Feldspar (formula: (K,Na)AlSi3O8)
Sandstone
Arenite
Sandstone (Ferruginous)
Arenite (primarily SiO2 with Fe2O3 staining)
Sandstone
Arenite (primarily SiO2)
Sandstone (with Iron Siderite Concretion)
Arenite with Ironstone Concretion (FeCO3)
Shale with Siltstone layering
Sedimentary Clastic Rock (Mudstone/Shale)
Quartz Pebble
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Rose Quartz
Silicon Dioxide (SiO2) with trace Titanium or Manganese
Carnelian Agate
Silicon dioxide (SiO2) - Chalcedony variety
Asphalt (Road Aggregate)
Asphalt concrete / Bituminous mixture
Garnet
Garnet Group (Silicate Minerals), formula varies e.g., Almandine Fe3Al2(SiO4)3
Sphalerite in Matrix (Polished Point)
Zinc sulfide (Zn,Fe)S
Diorite
Diorite (Intermediate plutonic rock)
Quartz Pebble
Silicon Dioxide (SiO2)
Quartz (pebble)
Quartz (SiO₂)
Rhodochrosite
Manganese Carbonate (MnCO3)
Assorted Decorative Tumbled Stones (Quartz, Sodalite, Aventurine, Calcite)
Mixed Silicates and Carbonates (SiO2, Na8(Al6Si6O24)Cl2, CaCO3)
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxide inclusions)
Slate
Slate (foliated metamorphic rock)
Chrysocolla and Malachite Beads
Hydrated copper silicates (Chrysocolla) and Copper carbonate hydroxide (Malachite)
Fossiliferous Chert (with Fossil Shells)
Silicon Dioxide (SiO2) with biogenic inclusions
Amygdaloidal Basalt
Vesicular Basalt with secondary mineral infilling (commonly Zeolite, Calcite, or Quartz)
Amethyst
Quartz variety; SiO2 (Silicon Dioxide)
Red Garnet (Pyrope or Almandine)
Garnet Group (A3B2(SiO4)3)
Sandstone with Liesegang Rings
Arenite with Iron Oxide Concretions
Sandstone (with potential iron-oxide weathering)
Arenite (SiO2 based)
Sandstone (Pebble/Conglomerate fragment)
Sandstone (clastic sedimentary rock)
Ferruginous Sandstone (Ironstone)
Clastic Sedimentary Rock (composed of SiO2 with Fe2O3/FeO(OH) cement)
Howlite
Calcium borosilicate hydroxide (Ca2B5SiO9(OH)5)
Sandstone
Clastic sedimentary rock (primarily SiO2)
Quartz Vein on Matrix
Silicon Dioxide (SiO2)
Sandstone
Arenite (SiO2 based with mineral cement)
Schist with Quartz Vein
Mica Schist with Crystalline Quartz (SiO2)
Amber
Succinite (with approximate formula C10H16O)
Gneiss (Metamorphic Rock)
Gneiss