Gold Nugget
Native Gold (Au)
mineral
Category
Mineral, Often A Rock Given Its Aggregate Nature
Browse mineral, often a rock given its aggregate nature specimens identified by the Rock Identifier community.
Jasper
Silicon Dioxide (SiO2) with iron oxide impurities
sedimentary
Sandstone (Pebble/Conglomerate fragment)
Sandstone (clastic sedimentary rock)
Sedimentary Rock
Conglomerate
Conglomerate (clastic sedimentary rock)
sedimentary
Sandstone with Secondary Mineral Encrustation
Arenite with Silica/Calcite deposits (SiO2 or CaCO3)
sedimentary
Breccia
Clastic Breccia (SiO2/CaCO3 dominated)
sedimentary
Jasper and Quartzite mix
Silicon Dioxide (SiO2) with impurities
sedimentary or metamorphic
Greenschist (Greenstone)
Greenschist (Metamorphic rock containing chlorite, actinolite, and epidote)
metamorphic
Painted River Pebble (likely Basalt or Greywacke)
Aphanitic Lithic Clast with Anthropogenic Pigment coating
Sedimentary or Igneous
Basalt
Vesicular Basalt (Mafic volcanic rock)
Igneous
Lapis Lazuli
Lapis Lazuli (A metamorphic rock primarily composed of Lazurite: (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2, along with Calcite and Pyrite)
metamorphic
Slickenside
Tectonic Fault Scarp Surface
metamorphic
River Pebble (Gabbro or Dark Sandstone variety)
Mafic Intrusive Rock (Plagioclase Feldspar and Pyroxene)
igneous
Bauxite (Laterite Clay)
Bauxite (mixture of Hydrous Aluminum Oxides: Gibbsite Al(OH)3, Boehmite and Diaspore AlO(OH))
sedimentary
Granite Pebble
Granite (Phaneritic intrusive igneous rock comprising Quartz, Feldspar, and Mica)
igneous
River Cobble (Quartzite with Iron Staining)
Metamorphic Quartzite (SiO2 with Fe2O3 inclusions)
metamorphic
Pyrite
Iron Sulfide (FeS2)
mineral
Chert (Iron-rich or Jasperoid)
Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (Flint/Jasper variety)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (River Pebble)
Microcrystalline quartz (SiO2)
sedimentary
Ironstone (with Limonite/Goethite)
Ferruginous Sedimentary Rock (contains Limonite FeO(OH)·nH2O and Hematite Fe2O3)
sedimentary
Greenschist (containing Epidote and Quartz)
Greenschist (Epidote-Chlorite-Actinolite Schist)
metamorphic
Sandstone
Sandstone (clastic sedimentary rock, composed predominantly of sand-sized minerals or rock fragments)
Sedimentary Rock
Chert (Jasper variety)
Silicon Dioxide (SiO2)
sedimentary
Brown Jasper
Jasper (a cryptocrystalline variety of Quartz, SiO2)
Mineral, specifically a variety of Quartz
Rhyolite
Rhyolite (Extrusive Igneous Rock)
igneous
Concrete / Conglomerate (Man-made)
Artificial Conglomerate (Cementitious Composite)
sedimentary
Jasper
Jasper (Silicon Dioxide, SiO2)
sedimentary
Jasper (specifically Red Jasper or Iron-stained Chert)
Silicon dioxide (SiO2) with iron oxide inclusions
sedimentary
Moss Agate
Moss Agate (a variety of Chalcedony, SiO ₂)
Mineral (specifically a variety of Chalcedony, which is microcrystalline Quartz)
Quartz (Float/Abraded)
Quartz (SiO₂)
Mineral
Banded Metamorphic Rock (likely Quartzite or Serpentinite/Soapstone)
Metamorphic Rock (possibly a banded Quartzite or a foliated Serpentinite/Talc Schist based on appearance, general term for such a rock is 'Banded Metamorphic Rock' or 'Gneiss' if pronounced banding of different minerals)
Metamorphic
Greenschist (Greenstone)
Greenschist
metamorphic
Quartz-Veined Mudstone
Argillaceous Mudstone with Quartz Veining
sedimentary
Sandstone (with potentially high Feldspar/Arkose content)
Clastic sedimentary rock (SiO2 dominated)
sedimentary
Gneiss
Gneiss (a metamorphic rock)
Metamorphic
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Biotite Mica
Biotite, K(Mg,Fe)3AlSi3O10(F,OH)2
mineral
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
mineral
Vesicular Basalt (or Scoria)
Basalt (Aphanitic-Vesicular Mafic Igneous Rock)
igneous
Conglomerate
Conglomerate (clastic sedimentary rock)
sedimentary
Quartzite pebble
Metamorphic rock (mainly SiO2)
metamorphic