Chert (often called Flint or Jasper)
Microcrystalline silica (SiO2)
Category
Browse organic gemstone (often associated with sedimentary sequences) specimens identified by the Rock Identifier community.
Chert (often called Flint or Jasper)
Microcrystalline silica (SiO2)
Chrysocolla and Azurite in Matrix
Hydrated copper phyllosilicate (Chrysocolla - Cu2H2Si2O5(OH)4) and Copper carbonate (Azurite - Cu3(CO3)2(OH)2)
Granite (tumbled pebble)
Granite (Plutonic Igneous Rock)
Jasper and Aquamarine (likely)
Jasper (Cryptocrystalline Quartz (SiO2)), Aquamarine (Beryl (Be3Al2Si6O18))
Chert (Jasper variety)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Stromatolite
Stromatolite (Cyanobacteria-formed Organo-sedimentary structure)
Quartz
Quartz (SiO2 - Silicon Dioxide)
Rutilated Quartz
SiO2 with TiO2 inclusions (Rutile)
Diorite (Dalmatian Stone)
Phaneritic Plutonic Diorite
Yellow Quartz (Citrine Quartz)
Silicon Dioxide (SiO2)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Blue Chalcedony
Chalcedony (SiO2)
Sandstone or Mudstone with Iron Staining
Ferruginous Sandstone/Mudstone
Serpentinite (often containing Jadeite/Nephrite)
Antigorite-rich Serpentine Rock, (Mg, Fe)3Si2O5(OH)4
Sodalite
Sodalite (Na8Al6Si6O24Cl2)
Labradorite (Gray Tumbled)
Labradorite (Ca,Na)(Al,Si)4O8
Fluorite
Calcium Fluoride (CaF2)
Unakite
Epidote-Feldspar rock
Sandstone (Ferruginous)
Sandstone (primarily SiO2 with Iron Oxide cement)
Sandstone
Arenite
Chert Pebble (Jasperoid/Flint)
Silicon Dioxide (SiO2) - cryptocrystalline quartz
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Blue Kyanite
Kyanite (Al2SiO5)
Petrified Wood
Silicified Wood (SiO2)
Turquoise (likely Sleeping Beauty variety or treated Howlite imitation)
Hydrated phosphate of copper and aluminium, CuAl6(PO4)4(OH)8·4H2O
Sandstone (likely Arkosic)
Clastic Sedimentary Rock (primarily SiO2 with Feldspar)
Petoskey Stone
Hexagonaria percarinata (Fossilized Coral)
Chert (and Jasper/Chalcedony mixture)
Microcrystalline Quartz (SiO2)
Diamond (Rough)
Diamond (C)
Orange Calcite
Calcium Carbonate (CaCO3)
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Manganese Ore (Psilomelane/Pyrolusite)
Psilomelane ((Ba,H2O)2Mn5O10) and Pyrolusite (MnO2)
Rough Quartz (likely Rose or Smoky variant)
Silicon Dioxide (SiO2)
Quartz Geode Fragment
Silicon Dioxide (SiO2)
Nephrite Jade (or Serpentine)
Nephrite (a variety of amphibole mineral tremolite-actinolite) or Serpentine Group minerals
Orange Calcite
Calcium Carbonate (CaCO3)
Chert (with small quartz inclusion)
Microcrystalline Silica (SiO2)
Jasper Shard / Chert
Silicon dioxide (SiO2)
Gneiss
Gneiss (pronounced 'nice')
Shale
Fissile Siliciclastic Sedimentary Rock
Quartz (Milky/Crystalline variety)
Silicon Dioxide (SiO2)
Quartz (in a rock matrix)
Quartz (SiO2)