Granite Cobble
Granite (Phaneritic Igneous Rock)
Category
Browse organic gemstone (not a rock or mineral) specimens identified by the Rock Identifier community.
Granite Cobble
Granite (Phaneritic Igneous Rock)
Precious Opal
Hydrated Silica (SiO2·nH2O)
Turquoise
Hydrated phosphate of copper and aluminium, CuAl6(PO4)4(OH)8·4H2O
Dendritic Agate
Silicon Dioxide (SiO2) with Manganese/Iron oxide inclusions
Sapphire (Raw/Rough)
Corundum (Al2O3)
Chalcedony (Banded/Mottled Variety)
Chalcedony (a cryptocrystalline variety of Quartz, SiO2)
Sandstone (Picture Sandstone)
Sandstone (primarily Quartz with Iron Oxide impurities)
Sandstone (Pebble)
Arenite (primarily SiO2)
Sandstone
Arenite (SiO2 principal)
Sandstone
Clastic sedimentary rock (primarily SiO2)
Sandstone
Arenite (primarily SiO2)
Blue Chalcedony
Silicon Dioxide (SiO2)
Sandstone (with man-made markings)
Arenite (composed primarily of Quartz, SiO2)
Sandstone
Arenite (primarily SiO2)
Coquina or Fossiliferous Limestone
Fossiliferous Calcarenite (CaCO3)
Chert (specifically Jasper or Brown Chert node)
Microcrystalline Quartz (SiO2)
Sandstone
Arenite
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Diorite
Phaneritic intermediate plutonic rock
Granodiorite
Granodiorite (intermediate plutonic rock)
Gneiss
Gneiss
Note on Image Identification: Textile
N/A (Anthropogenic material)
Citrine
Silicon Dioxide (SiO2) - Macrocrystalline Quartz variety
Spinel
Magnesium Aluminum Oxide (MgAl2O4)
Basalt
Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)
Sandstone
Arenite (primarily SiO2)
Sandstone (likely with Quartz Veining)
Arenite (primarily SiO2)
Amygdaloidal Basalt with Zeolite/Quartz Infill
Amygdaloidal Basalt (Host: (Mg,Fe)2SiO4 / CaAl2Si2O8; Infill: SiO2 or Na2Al2Si3O10·2H2O)
Shale
Fissile Mudrock (Clay-rich Sedimentary Rock)
Bauxite
Bauxite (Al(OH)3, AlO(OH))
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Red Sandstone (Old Red Sandstone)
Ferruginous Sandstone (SiO2 + Fe2O3)
Baltic Amber (Butterscotch variety)
Succinite
Baltic Amber (Butterscotch or Egg Yolk Variety)
Succinite (C10H16O)
Amber
Succinite (Formula: C10H16O)
Basalt with Hematite staining
Extrusive mafic igneous rock with Fe2O3
River Pebble (Likely Chert or Fine-Grained Sandstone/Quartzite)
Siliciclastic clast (likely Chert or Quartzarenite/Quartzite pebble)
Moonstone
Orthoclase (KAlSi3O8), specifically the variety showing adularescence
Sodalite
Sodalite - Na8(Al6Si6O24)Cl2
Larimar
Pectolite (Blue variety), NaCa2Si3O10(OH)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Almandine Garnet
Almandine, Fe3Al2(SiO4)3