Pumice
Vesicular Rhyolite or Dacite
Category
Browse igneous or sedimentary (water worn) specimens identified by the Rock Identifier community.
Pumice
Vesicular Rhyolite or Dacite
Quartz crystals on Basalt
SiO2 (Quartz) on Mafic Igneous Rock (Basalt)
Limestone
Sedimentary rock composed primarily of Calcium Carbonate (CaCO3)
Sandstone (Weathered Pebble)
Arenite (SiO2 primarily)
Sandstone (Ferruginous)
Arenite with Iron Oxides
Crushed Limestone
Calcium Carbonate (CaCO3)
Limestone
Calcium Carbonate (CaCO3)
Chert (Yellow Jasper/Flint pebble)
Microcrystalline Quartz (SiO2)
Amber
Succinite
Concrete / Conglomerate (Man-made)
Artificial Conglomerate (Cementitious Composite)
Red Jasper (with inclusions)
Silicon Dioxide (SiO2) with Hematite impurities
Jasper (Iron-rich)
Silicon Dioxide (SiO2) with Hematite (Fe2O3) impurities
Jasper
Silicon dioxide (SiO2) with impurities
Yellow Jasper (Chert variant)
Silicon Dioxide (SiO2) with iron inclusions
Vesicular Basalt with Oxidation
Scoriaceous Olivine Basalt (Mafic volcanic rock)
Basalt with Secondary Mineralization (Likely Zeolites or Calcite)
Aphanitic mafic volcanic rock with secondary mineral inclusions (e.g., CaAl2Si3O10·3H2O for Scolecite)
Sandstone (Tumbled/River Pebble)
Arenite (composed primarily of SiO2)
Sandstone
Clastic Sedimentary Rock (primarily SiO2)
Tektite (Indochinite)
Tektite (Amorphous Silica Glass), SiO2(Al2O3)
Basalt River Rock
Basalt (Aphanitic Mafic Igneous Rock)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Conglomerate
Conglomerate (Clastic Sedimentary Rock)
Rough Garnet (likely Almandine or Pyrope)
Garnet group; Almandine Fe3Al2(SiO4)3 or Pyrope Mg3Al2(SiO4)3
Nobby Hematite (Iron Ore)
Hematite (Fe2O3)
Quartz Geode
Silicon Dioxide (SiO2)
Chalcedony (Common Opal variant)
Silicon dioxide (SiO2) with microcrystalline structure
Pyrite on Limestone
Iron Disulfide (FeS2) in Calcium Carbonate (CaCO3) matrix
Jasper
Silicon dioxide (SiO2) with iron oxide inclusions
Hematite
Hematite (Fe2O3)
Amber
Organic gemstone (Succinite is common if from the Baltic)
Amber
Succinite (specifically for Baltic Amber), Formula: C10H16O
Barite Rose on Marcasite
Barium Sulfate (BaSO4) on Iron Sulfide (FeS2)
Amazonite
Amazonite / Microcline (KAlSi3O8)
Conglomerate
Conglomerate (clastic sedimentary rock)
Travertine (Tufa)
Chemical Sedimentary Limestone (CaCO3)
Chert (or Flint)
Chert (Sedimentary Cryptocrystalline Sio2)
Sandstone-based Concrete Fragment
Cementitious Composite with Sedimentary Aggregate
Conglomerate
Conglomerate (Clastic sedimentary rock)
Granite or Granitic Gneiss River Rock
Granite / Gneiss
Obsidian
Obsidian (Amorphous volcanic glass)
Pegmatite
Pegmatitic Granite
Feldspar-rich Pegmatite
Granitic Pegmatite (principally KAlSi3O8)