Hag Stone
Perforated sedimentary rock (typically limestone, sandstone, or flint)
Category
Browse synthetic (not a natural rock) specimens identified by the Rock Identifier community.
Hag Stone
Perforated sedimentary rock (typically limestone, sandstone, or flint)
Blue Agate (Dyed Chalcedony)
Silicon Dioxide (SiO2)
Smoky Quartz (Tumbled)
Silicon Dioxide (SiO2)
Sandstone (Quartzite-rich)
Clastic Sedimentary Rock (primarily SiO2)
Pumice
Pumicite (Volcanic glass with vesicular texture)
Quartzite Pebbles or River Rock
Quartzite / Microcrystalline Quartz (SiO2)
Sandstone (with Iron Staining)
Clastic Sedimentary Rock (primarily SiO2 with Fe2O3 oxides)
Yellow Quartz (Citrine or Iron-Stained Quartz)
Silicon Dioxide (SiO2)
Sandstone (Ferruginous)
Arenite (with Iron Oxide)
Sapphire
Corundum (Al2O3)
Blue Sapphire
Corundum (Al2O3)
Pet Rock (Man-made Quartzite or Granite Cobble)
Silicon dioxide (SiO2) mixture; commonly composed of Quartz, Feldspar, and Mica
Sandstone (Ferruginous)
Arenite (with Iron Oxide cement)
Amethyst Geode
Amethyst (Silicon Dioxide, SiO2)
Quartz Crystal (specifically a Double-Terminated variety)
Silicon Dioxide (SiO2) - Low Quartz
Sandstone
Clastic Sedimentary Rock
Sandstone
Clastic Sedimentary Rock
Granite
Intrusive Phaneritic Felsic Igneous Rock
Smoky Quartz in Matrix
Silicon dioxide (SiO2) within Pegmatite/Gneiss
Milky Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
Carnelian and Strawberry Quartz
Silicon Dioxide (SiO2) with Hematite and Limonite inclusions
Bauxite (Pisolitic Bauxite)
Bauxite (mixture of Hydrous Aluminum Oxides)
Blue Obsidian
Volcanic Glass (SiO2 with inclusions)
Boulder Opal
Hydrated amorphous silica (SiO2·nH2O) in ironstone matrix
Sandstone (Ferruginous)
Clastic sedimentary rock (primarily SiO2 with Fe2O3 cement)
Golden Healer Quartz
Silicon Dioxide (SiO2) with Hematite/Limonite inclusions
Sandstone
Arenite
Green Aventurine
Silicon Dioxide (SiO2) with inclusions
Basalt
Basalt
Blue Obsidian (Cullet Glass)
Silicon Dioxide (Amorphous Glass)
Sandstone Cobble with Iron Staining
Arenite with Limonite/Goethite coatings
Turquoise
Turquoise, CuAl6(PO4)4(OH)8·4H2O
Quartz (specifically Citrine or Yellow Quartz)
Silicon Dioxide (SiO2)
Granite Gravel (Pebble)
Intrusive Felsic Igneous Rock
Granite
Felsic Plutonic Igneous Rock
Conglomerate
Conglomerate (Sedimentary Clastic Rock)
Granite
Intrusive igneous felsic rock
Granite
Phaneritic Plutonic Felsic Rock
Granite
Phaneritic Felsic Igneous Rock
Granite
Phaneritic plutonic rock (Felsic)
Sandstone
Sandstone (SiO2 dominant)
River Rock
Polished Siliceous Rock / Quartzite Pebble