Obsidian
Volcanic glass (SiO2 - Silicon Dioxide with impurities)
Category
Browse sedimentary (secondary mineral formation) specimens identified by the Rock Identifier community.
Obsidian
Volcanic glass (SiO2 - Silicon Dioxide with impurities)
Red Quartzite
Quartzite (SiO2 with iron oxide impurities)
Sandstone
Arenite (general term for sandstone)
Sandstone
Arenite
Amethyst/Smoky Quartz Cluster
Silicon Dioxide (SiO2)
Pink Satin Spar (Satin Spar Selenite Dyed)
Gypsum (CaSO4·2H2O)
Hematite
Iron(III) oxide (Fe2O3)
Howlite
Howlite (Ca2B5SiO9(OH)5)
Halite (Rock Salt)
Halite (Sodium Chloride, NaCl)
Orange Calcite (Cleavage Rhomb)
Calcite (Calcium Carbonate, CaCO3)
Sandstone (Quartz Sandstone)
Arenite (primarily SiO2)
Agate
Agate (Cryptocrystalline Variety of Quartz, SiO2)
Sandstone
Arenite (primarily SiO2)
Tiger's Eye
Pseudomorph of quartz after crocidolite (SiO2 with iron oxide inclusions)
Clear Quartz
Silicon Dioxide (SiO2)
Shale
Clastic sedimentary rock (primarily clay and silt minerals)
Quartzite Pebble
Metamorphosed Quartz Sandstone (SiO2)
Rutilated Quartz
SiO2 with TiO2 inclusions (Rutile)
Smoky Quartz
Smoky Quartz (SiO2)
Amazonite
KAlSi3O8 (Potassium Feldspar, variety of Microcline)
Satin Spar (Gypsum)
Calcium Sulfate Dihydrate (CaSO4·2H2O)
Blue Howlite (Dyed)
Calcium Borosilicate Hydroxide (Ca2B5SiO9(OH)5)
Tumbled Moonstone and Amazonite Chips
Orthoclase (KAlSi3O8) and Microcline (KAlSi3O8) of the Feldspar Group
Clear Quartz (Tumbled)
Quartz (Silicon Dioxide - SiO2)
Botryoidal Chalcedony (Desert Rose / Grape Agate variant)
Silicon Dioxide (SiO2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Granite
Granite (felsic intrusive igneous rock)
Sandstone (Banded)
Clastic Sedimentary Rock: Arenite
Jade (likely Jadeite)
Jadeite (a pyroxene mineral) or Nephrite (a variety of amphibole mineral)
Quartzite (specifically Pink or Red Quartzite)
Metamorphosed Quartz Sandstone (SiO2)
Pyrite (on Shale/Matrix)
Iron Disulfide (FeS2)
Pyrite
Iron Sulfide (FeS2)
Satin Spar Selenite
Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O
Shale with Siltstone layering
Sedimentary Clastic Rock (Mudstone/Shale)
Sandstone (with ripple marks)
Arenite / Quartz Sandstone
Red Quartzite Slipper Stone
Quartzite (SiO2)
River Pebble (Likely Quartzite or Chalcedony)
Silicon Dioxide (SiO2) - granular metamorphic variety
Sandstone (likely with Quartz Veining)
Arenite (primarily SiO2)
Barite Rose on Marcasite
Barium Sulfate (BaSO4) on Iron Sulfide (FeS2)
Jasper in Basalt Matrix
Silicon Dioxide (SiO2) with impurities; Chalcedony
Grey River Stone (Gneiss/Schist mix)
Foliated Metamorphic Rock (variable mineral formula)
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)