Dendrite (Manganese Oxide Dendrites)
Psilomelane or Pyrolusite on Matrix (typically MnO2)
mineral
Category
Sedimentary Rock
Browse sedimentary rock specimens identified by the Rock Identifier community.
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Chert (Fossiliferous)
Chert (Cryptocrystalline Silica/SiO2)
sedimentary
Chert (specifically a fragment with Desert Varnish)
Microcrystalline quartz (SiO2)
sedimentary
Turquoise
Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)
mineral
Quartzite
Quartzite (primarily SiO2)
metamorphic
Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
metamorphic
Quartz Vein in Schist
Quartz (SiO2) in Pelitic Schist
metamorphic
Ferruginous Sandstone (Iron-rich Sandstone)
Ferruginous Arenite
sedimentary
Quartz Pebble (Geode-like)
Silicon Dioxide (SiO2)
Mineral
Coral Rock (Coquina)
Biogenic Limestone (Calcium Carbonate - CaCO3)
sedimentary
Quartz (Milky/Crystal Variety)
Silicon Dioxide (SiO2)
mineral
Chert (specifically Gray/Tan Bedded Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Chert
Microcrystalline Quartz (SiO2)
sedimentary
Red Sandstone
Arenite (high iron oxide content)
sedimentary
Banded Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
metamorphic
Banded Agate (specifically Carnelian Agate)
Silicon Dioxide (SiO2) - Chalcedony variety
mineral
Clear Quartz Geode
Crystalline Silicon Dioxide (SiO2)
mineral
Sandstone with Vitrinite/Coal inclusions
Arenite with Carbonaceous inclusions
sedimentary
Graphite Schist
C (Carbonaceous Schist)
metamorphic
Quartz (Orthoquartzite)
Silicon Dioxide (SiO2)
sedimentary
Chert (with Manganese Oxide coating)
Microcrystalline Quartz (SiO2)
sedimentary
Hardened Gray Mudstone
Argillite / Silicified Mudstone (principally SiO2 and Al2Si2O5(OH)4)
sedimentary
Tufa
Calcareous Tufa (Calcium carbonate, CaCO3)
sedimentary
Jasper (Red/Brown Variety)
Jasper (Silicon Dioxide, SiO2 plus Iron Oxide impurities)
sedimentary
Sandstone (specifically Cross-bedded Sandstone)
Arenite (composed primarily of SiO2)
sedimentary
Ferruginous Sandstone
Arenite with Iron Oxide cement (primarily Fe2O3)
sedimentary
Jasper
Silicon dioxide (SiO2) with iron impurities
sedimentary
White Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
mineral
Gneiss
Gneiss
metamorphic
Quartzite (River Pebble)
Metamorphosed Sandstone (SiO2)
metamorphic
Petrified Wood
Silicified Wood (SiO2)
mineral
Chert (often called Jasper or River Siltstone)
Microcrystalline Quartz (SiO2)
sedimentary
Quartz Geode
Crystalline Silicon Dioxide (SiO2) in Geode form
sedimentary
Carnelian
Carnelian (Cryptocrystalline Quartz, SiO2)
mineral
Quartz Geode
Silicon Dioxide (SiO2)
mineral
Chalcedony (Botryoidal/Agate nodule)
Microcrystalline Quartz (SiO2)
mineral
Banded Agate (with Quartz Geode Center)
Silicon Dioxide (SiO2)
mineral
Quartz Geode
Silicon Dioxide (SiO2)
mineral
Red Jasper
Jasper (SiO2) with Hematite (Fe2O3) inclusions
sedimentary (microcrystalline quartz)
Gneiss
Gneiss (High-grade regional metamorphic rock)
metamorphic
Jasper Agate (specifically Brecciated Jasper)
Silicon Dioxide (SiO2) with iron oxide and clay impurities
sedimentary
Yellow Jasper
Silicon Dioxide (SiO2)
sedimentary