Petrified Wood
Silicified Wood (primarily SiO2)
Category
Browse organic (non geological) specimens identified by the Rock Identifier community.
Petrified Wood
Silicified Wood (primarily SiO2)
Limonite (Yellow Ochre)
Hydrated iron(III) oxide-hydroxide (FeO(OH)·nH2O)
Rough Green Beryl (Emerald variety)
Beryl (Be3Al2Si6O18 with Chromium/Vanadium impurities)
Blue Goldstone
Aventurine Glass (Silicon Dioxide infused with Cobalt/Copper)
River Siltstone / Mudstone Pebble
Siltstone (composed of mixed silicate and carbonate minerals)
Quartzite
Metamorphic Quartzite (primarily SiO2)
Quartzite
Quartzite (primarily SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert (containing Flint and Calcareous inclusions)
Silicon Dioxide (SiO2) with Calcium Carbonate (CaCO3) impurities
Red Jasper
Microcrystalline Quartz (SiO2) with Hematite impurities
Metaconglomerate
Protolith: Conglomerate (comprising SiO2, Al2O3, etc.)
Obsidian
Obsidian (Volcanic Glass)
Tiny metallic mineral fragment, possibly native gold
Native gold (Au), unconfirmed; could also be pyrite or chalcopyrite
Slag Glass
Amorphous Silica Glass (with metal oxide inclusions)
Fossilized Coral
Cnidaria (Anthozoa), often replaced by Calcium Carbonate (CaCO3) or Silica (SiO2)
Chert (Jasper/Flint variant)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Moss Agate
Silicon Dioxide (SiO2) with Manganese or Iron Oxide inclusions
Quartzite
Quartzite (SiO2)
Ferruginous Quartzite (Red Quartzite)
Quartzite (primarily SiO2 with Fe2O3 inclusions)
Quartzite
Quartzite (SiO2)
Quartzite
Quartzite (primarily SiO2)
Fossiliferous Limestone
Biogenic Sedimentary Rock (CaCO3)
Man-made Crystal (Lead Glass)
Lead oxide-doped Silica Glass (approx. SiO2 + PbO)
Fossilized Brain Coral
Diploria labyrinthiformis (Fossilized)
Piddock-bored Mudstone
Lutite (Siltstone or Mudstone) with Pholad borings
Opalite (Man-made Glass)
Synthetic Silicon Dioxide Glass (SiO2 + metal oxides)
Quartzite
Metamorphosed Sandstone (Mainly SiO2)
Petrified Wood
Silicified Wood (primarily SiO2)
Moqui Marbles
Iron Oxide Concretion (Hematite/Goethite)
Siltstone or Fine-grained Sandstone pebble
Siltstone (primarily SiO2 with clay minerals)
Chert with Limestone Cortex
Silicon Dioxide (SiO2) with Calcium Carbonate (CaCO3)
Chert (Concretion or Nodular Variety)
Microcrystalline Quartz (SiO2)
Green Chert
Microcrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Petrified Wood
Silicified Wood (primarily SiO2)
Obsidian
Volcanic Glass (Amorphous SiO2)
Black Obsidian
Volcanic Glass (Amorphous Silicon Dioxide)
Obsidian
Volcanic Glass (Primary component: SiO2)
Limestone (with Chert)
Calcium Carbonate (CaCO3) / Microcrystalline Quartz (SiO2)
Flint / Chert Nodule
Microcrystalline quartz (SiO2)
Shale
Mudrock / Fissile Shale