River Cobble (likely Metasedimentary or Basalt)
Metamorphosed Siltstone or Altered Fine-grained Igneous Rock
Category
Browse sedimentary rock (technically chert, a microcrystalline quartz) specimens identified by the Rock Identifier community.
River Cobble (likely Metasedimentary or Basalt)
Metamorphosed Siltstone or Altered Fine-grained Igneous Rock
Banded Slate or Siltstone with Quartz/Calcite Veins
Protolith-derived Siltstone or Slate (varies based on degree of metamorphism)
Chert (specifically Yellow Jasper variety)
Silicon Dioxide (SiO2)
Quartz in Limonite-rich Matrix
Silicon Dioxide (SiO2) with Goethite/Limonite FeO(OH)·nH2O
Sandstone (Ferruginous)
Clastic Sedimentary Rock (SiO2 with Fe2O3/FeOOH cement)
Chert (Jasper)
Microcrystalline Silica (SiO2)
Pink Tumbled Agate
Microcrystalline Quartz (SiO2)
Quartz (Druzy on Matrix)
Silicon Dioxide (SiO2)
Sandstone (likely Arkose or Quartz Sandstone)
Arenite (SiO2 + varied clasts)
Chert (specifically Gray Chert)
Silicon Dioxide (SiO2)
Quartzite
Quartzite (primarily SiO2)
Graphite-veined Quartzite
Meta-sedimentary Quartzite with Carbonaceous/Graphitic Inclusions (SiO2 + C)
Sandstone
Arenite (Sedimentary Rock)
Chert (Jasper/River Pebble)
Silicon Dioxide (SiO2)
Chert (and Flint)
Silicon Dioxide (SiO2)
Quartzite River Rock
Quartzite (SiO2)
Quartz Vein in Siltstone
Silicon Dioxide (SiO2) within Sedimentary/Metamorphic Matrix
Quartzite
Quartzite (primarily SiO2)
Obsidian
Obsidian (Amorphous volcanic glass, SiO2 rich)
Limonite (Iron Ore)
Limonite (̑FeO(OH)·nH₂O)
Tree Agate
Dendritic Agate (Silicon Dioxide, SiO2 + Manganese/Iron oxides)
Agate Geode
Silicon Dioxide (SiO2)
Chert (Flint)
Chert (Silica, SiO2)
Chert (Jasper)
Cryptocrystalline Quartz (SiO2)
Chert (Nodular)
Cryptocrystalline Quartz (SiO2)
Shale
Fissile Mudstone
Sandstone
Arenite
Chalcedony Geode Fragment
Microcrystalline Quartz (SiO2)
Red Quartzite
Quartzite (primarily SiO2 with hematite impurities)
Quartz Geode
Silicon Dioxide (SiO2) in Host Rock
Banded Agate
Cryptocrystalline Silica (SiO2)
Clear Quartz Geode
Crystalline Silicon Dioxide (SiO2)
Ocean Jasper or Orbicular Jasper
SiO2
Chert (specifically Dark Chert or Flint)
Silicon dioxide (SiO2)
Lapis Lazuli (Lazurite crystals on Marble)
Lazurite / (Na,Ca)8[(S,Cl,SO4,OH)2|(AlSiO4)6]
Sandstone Chert/Quartzite
Silicon Dioxide (SiO2) - Sedimentary Sandstone / Orthoquartzite
Red Jasper
Silicon Dioxide (SiO2) with Iron inclusions
Quartzite with Iron Inclusions
Quartzite (primarily SiO2)
Shiva Lingam
Cryptocrystalline Quartz (Jasperiod Siltstone)
Chert (Flint)
Cryptocrystalline Quartz (SiO2)
Chert (Flint)
Cryptocrystalline Quartz (SiO2)
Chert (Jasper)
Cryptocrystalline Quartz (SiO2)