Sandstone
Arenite (primarily SiO2)
Category
Browse organic (non geological) specimens identified by the Rock Identifier community.
Sandstone
Arenite (primarily SiO2)
Quartz (Milky/Yellowish variety)
Silicon Dioxide (SiO2)
Rose Quartz
SiO2 (Silicon Dioxide with trace amounts of titanium, iron, or manganese)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Sandstone Concretion
Clastic Sedimentary Concretion (typically Quartz/Silica with Iron Oxide)
Gold Nugget
Native Gold (Au)
Gold
Native Gold (Au)
Chalcedony in Host Rock
Chalcedony (SiO2)
Yellow Jasper
Silicon dioxide (SiO2)
Nickel coin (U.S. currency)
Cupronickel (75% Copper, 25% Nickel alloy)
Quartz Geode Fragment
Silicon Dioxide (SiO2)
Man-made Synthetic Material (Not a rock or mineral)
Polyester (Polyethylene terephthalate) / Faux Fur
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
Quartz (Milky/Smoky variety)
Silicon Dioxide (SiO2)
Gold Nugget
Native Gold (Au)
Obsidian
Volcanic Glass (SiO2 rich)
Quartz Mineral
Silicon Dioxide (SiO2)
Quartz Geode
Silicon Dioxide (SiO2)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Chert (Jasper)
Silicon Dioxide (SiO2) with impurities
Obsidian (Black)
Obsidian (approx. 70–75% SiO2)
Gold Nugget
Native Gold (Au)
Placer Gold Nugget
Native Gold (Au)
Fossilized Rugose Coral (Petoskey Stone precursor)
Hexagonaria percarinata (Fossilized Rugose Coral)
Chalk (Limestone variant)
Calcium Carbonate (CaCO3)
Chalk (Sedimentary Pebble)
Calcium Carbonate (CaCO3) - Biogenic Limestone
Granite
Granite (composed primarily of Quartz SiO2, Alkali Feldspar KAlSi3O8, and Plagioclase Feldspar)
Milky Quartz
Quartz (Silicon Dioxide - SiO2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Iron Meteorite
Iron-nickel alloy (primarily kamacite and taenite)
Quartz (Iron-stained)
Silicon Dioxide (SiO2)
Granite
Granite (Felsic Plutonic Rock)
Garnet
Garnet Group (formula varies, e.g., Almasndine: Fe3Al2(SiO4)3)
Quartz (Chatoyant or Milky variety)
Silicon Dioxide (SiO2)
Milky Quartz
Quartz (Silicon Dioxide - SiO2)
Sandstone
Arenite
Red Sandstone (Old Red Sandstone Pebble)
Arenite with iron oxide (Fe2O3) cement
Chevron Amethyst
Silicon Dioxide (SiO2) with iron impurities
Horn Coral Fossil
Rugosa (Order Rugosa)
Gold Nugget
Native Gold (Au)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)