Brown Jasper (Chert)
Silicon Dioxide (SiO2)
Community gallery
Every specimen the Rock Identifier community has discovered, from desert agates to deep-sea basalts.
Brown Jasper (Chert)
Silicon Dioxide (SiO2)
Gneiss
Gneiss (High-grade metamorphic rock)
Banded Gneiss
Gneiss (High-grade metamorphic rock)
Limonite/Goethite Concretion
Hydrated Iron(III) Oxide-hydroxide (FeO(OH)·nH2O)
Chert (River Pebble)
Microcrystalline Quartz (SiO2)
Granite River Pebble
Phaneritic Felsic Igneous Rock (Granite)
River Stone (Grey Andesite)
Intermediate extrusive volcanic rock (Andesite)
River Pebble (Greywacke or Chert mix)
Silicon Dioxide (SiO2) with varying mineral impurities
Milky Quartz with Iron Oxide
Quartz (Silicon Dioxide, SiO2) with Limonite/Goethite staining
Ferruginous Quartz
Silicon Dioxide (SiO2) with Hematite/Limonite impurities
Red Jasper
Silicon Dioxide (SiO2)
Chert (Nodule)
Chert (Silicon dioxide, SiO2)
Fossilized Tabulate Coral (Honeycomb Coral)
Favosites (Order: Tabulata)
Petoskey Stone
Hexagonaria percarinata (Fossilized Rugose Coral)
Quartzite
Metamorphosed Quartz Sandstone (SiO2)
Ironstone Concretion
Siderite or Goethite Concretion
Fossilized Bone (Petrified Bone)
Permineralized Vertebrate Remains
Fossilized Bone
Permineralized Vertebrate Fossil
Chert with Crinoid Fossil Impression
Microcrystalline Quartz (SiO2) with Crinoidea fossil impression
Sandstone (with potential iron mineralization)
Arenite
Iceland Spar (Optical Calcite)
Calcite (Calcium Carbonate, CaCO3)
Obsidian
Volcanic glass (SiO2-rich)
Fluorite Octahedron
Fluorite (Calcium Fluoride, CaF2)
Petrified Wood (Agatized/Silicified Wood)
Silicified Paleoxylon (primarily SiO2)
Almandine Garnet
Almandine (Fe3Al2Si3O12)
Petrified Wood (Agatized/Silicified Wood)
Silicified Wood (SiO2)
Optical Calcite
Calcium Carbonate (CaCO3)
Conglomerate
Conglomerate
Green Aventurine
SiO2 (Silicon Dioxide with Fuchsite inclusions)
Carnelian
SiO2 (Silicon Dioxide with Iron Oxide impurities)
Green Aventurine
Quartz (SiO2) with Fuchsite inclusions
Quartz Geode
Crystalline Silicon Dioxide (SiO2) in Geode form
Obsidian
Volcanic Glass (SiO2)
Rhyolite
Rhyolite (High-silica volcanic rock)
Blue Tiger's Eye (Hawk's Eye)
Pseudomorph of Quartz after Crocidolite (SiO2)
Tiger's Eye
Silicon Dioxide (SiO2) with fibrous inclusions of Crocidolite
Citrine Quartz
Silicon Dioxide (SiO2)
Citrine Quartz
Silicon Dioxide (SiO2)
Clear Quartz
Silicon Dioxide (SiO2)
Agate
Chalcedony (SiO2)
Pebble (likely Limestone or Siltstone)
Lithic fragment (calcareous or siliciclastic)
Basalt
Basalt