Obsidian
Volcanic Glass
igneous
Category
Synthetic Material (Not A Rock Or Mineral)
Browse synthetic material (not a rock or mineral) specimens identified by the Rock Identifier community.
Learn about Synthetic Material (Not A Rock Or Mineral) in the encyclopedia
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Sandstone (with Iron Staining)
Arenite (Silicon Dioxide, SiO2, often with iron oxides like Limonite)
sedimentary
Tumbled orange chalcedony (likely carnelian)
Microcrystalline quartz, SiO₂; iron-bearing variety commonly termed carnelian
mineral
Sandstone (Ferruginous)
Arenite with Hematite cement (SiO2 + Fe2O3)
sedimentary
Sandstone (Ferruginous)
Arenite (primarily SiO2 with Fe2O3 staining)
sedimentary
Sandstone
Arenite (predominantly SiO2 with iron oxides)
sedimentary
Petrified Wood
Silicified Wood (primarily SiO2 - Silicon Dioxide)
sedimentary
Sandstone (Limonitic/Arkose)
Sandstone (primarily SiO2 with FeO(OH)·nH2O)
sedimentary
Sandstone (Red)
Arenite (SiO2 with Fe2O3)
sedimentary
Quartz Grain
Silicon Dioxide (SiO2)
mineral
Sandstone (Stream-rounded Cobble)
Arenite (composed primarily of SiO2, Silica)
sedimentary
Sandstone (with Iron Staining)
Clastic sedimentary rock (primarily Quartz with Hematite/Limonite oxides)
sedimentary
Quartz Pebble
Crystalline Silica (SiO2)
sedimentary
Sandstone
Arenite
sedimentary
Sandstone (Red/Brown Variety)
Arenite (SiO2 with iron oxide impurities)
sedimentary
Sandstone (likely with Borings or Vesicular Basalt)
Clastic Sedimentary Rock (Sandstone)
sedimentary
Sandstone (Quartzite-rich)
Clastic Sedimentary Rock (primarily SiO2)
sedimentary
Sandstone with Iron Weathering
Quartz Arenite / Weathered Sandstone
sedimentary
Quartz with Iron Oxide
Silicon Dioxide (SiO2) with Fe2O3 inclusions
mineral
Quartz crystal pendant
Quartz (silicon dioxide, SiO₂), likely rock crystal or milky quartz
mineral
Limestone (Weathered)
Sedimentary Carbonate Rock (CaCO3)
sedimentary
Green aventurine (likely)
Quartzite dominated by quartz (SiO₂), colored green by fuchsite mica or chlorite
mineral
Diorite (River Pebble)
Intermediate Phaneritic Igneous Rock
igneous
Quartz (Iron-stained)
Silicon Dioxide (SiO2)
mineral
Tumbled jasper or chert
Microcrystalline quartz (SiO₂), possibly iron-bearing jasper
mineral
Sandstone (likely Arkose or Quartz Sandstone)
Arenite (SiO2 principal component)
sedimentary
Shale
Argillite / Shaly Mudstone
sedimentary
Emerald in Matrix
Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities
mineral
Aventurine
Quartz (SiO2) with Fuchsite inclusions
mineral
Petrified Wood
Silicified wood (primarily quartz, SiO2)
fossil
Weathered granitic rock
Granite or granodiorite, likely quartz–feldspar–mica aggregate
igneous
Tumbled green aventurine (probable)
Quartzite dominated by quartz (SiO₂), with green mica/fuchsite or chlorite inclusions
mineral
Petrified Wood
Silicified Wood (primarily Quartz/SiO2)
mineral
Sandstone (River Rock)
Arenite (SiO2 based sedimentary rock)
sedimentary
Goldstone (Red)
Aventurine Glass (Cupriferous glass)
Synthetic Glass (Man-made)
Sandstone (Quartzose)
Arenite (primarily SiO2)
sedimentary
Quartz geode
Microcrystalline quartz and drusy quartz (SiO₂), commonly lining a chalcedony-rich cavity
mineral
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Yellow Ocher (Iron-rich Silt/Clay)
Goethite-rich Limonite (FeO(OH)qnH2O)
sedimentary
Chert (Chalcedony/Agate variety)
Silicon Dioxide (SiO2)
sedimentary
Amygdaloidal Basalt
Amygdaloidal Basalt with Secondary Mineral Amygdules
igneous
Serpentine (Serpentinite)
Hydrous magnesium iron silicate, (Mg,Fe)3Si2O5(OH)4
metamorphic