Red Jasper
Silicon dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions
sedimentary
Category
Sedimentary (Chemically Precipitated)
Browse sedimentary (chemically precipitated) specimens identified by the Rock Identifier community.
Red Jasper
Silicon dioxide (SiO2) with iron oxide (Fe2O3) inclusions
sedimentary
Microcrystalline Limestone Pebble
Carbonate sedimentary rock (Calcium Carbonate, CaCO3)
sedimentary
Chert (specifically Jasper or Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Quartz Pebble (Milky and Gray)
Quartz (Silicon Dioxide, SiO2)
mineral
Agate
Silicon Dioxide (SiO2) - Cryptocrystalline Chalcedony
Mineral
Ferruginous Quartz (Carnelian-tinted Quartz)
Silicon Dioxide (SiO2) with Iron Oxide inclusions
mineral
Native Sulfur
Sulfur (S8)
mineral
Coal (most likely Bituminous or Anthracite)
Coal (organic sedimentary rock)
Sedimentary
Unidentifiable Rock Fragment
Uncertain
Sandstone
Sandstone (Clastic Sedimentary Rock)
Sedimentary Rock
Sandstone (likely a river or beach pebble)
Sandstone (a clastic sedimentary rock)
Sedimentary Rock
Wood Jasper
Siliceous sedimentary rock (variety of Chert/Chalcedony)
Sedimentary
Travertine (used in construction, not a 'specimen' in situ)
Travertine
Sedimentary
Chert (specifically a stream-worn Chert Nodule)
Sedimentary Cryptocrystalline Quartz (SiO2)
sedimentary
Quartz
Quartz (SiO₂ - Silicon Dioxide)
Mineral
Gray Quartz (Tumbled)
Silicon Dioxide (SiO2)
mineral
Graphite
Graphite (Native Carbon, C)
metamorphic
Quartz Pebble (Chalcedony/Agate variety)
Silicon Dioxide (SiO2)
mineral
Magnetite
Magnetite (Fe3O4)
Mineral
Agate Geode
Chalcedony (SiO2 - Silicon Dioxide)
sedimentary (secondary mineral formation)
Quartz (likely)
Quartz (SiO2 - Silicon Dioxide)
Mineral
Quartz
Quartz (SiO₂)
Mineral
Iron Ore / Ironstone Concretion
Mixture of iron oxide/hydroxide minerals, likely some combination of Hematite (Fe2O3), Goethite (α-FeOOH), and Limonite (a general term for hydrated iron oxides of variable composition) or potentially Bauxite (a mixture of aluminum hydroxides, often with iron oxides, (Al(OH)3) and FeO(OH)). The visual characteristics strongly suggest iron-rich material.
Mineral, specifically an iron ore
Slate
Slate (Foliated Metamorphic Rock)
metamorphic
Blue Agate (Dyed)
Silicon Dioxide (SiO2)
Sedimentary (formed from silica deposits)
Banded Agate (Onyx variety)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
mineral
Druzy Quartz on Host Rock
Silicon Dioxide (SiO2) with various iron-oxide inclusions
mineral
Quartzite
Quartzite
Metamorphic rock
Calcite (likely a tumbled specimen)
Calcite (CaCO 3 )
Mineral
Chert / Flint (a variety of Chert)
Chert (SiO2)
Sedimentary Rock (technically a microcrystalline quartz mineral aggregate)
Jasper and Basalt Mix (Dark Chert/Basalt River Pebble)
Silicon Dioxide (SiO2) or Mafic extrusive igneous rock
sedimentary or igneous
Quartz
Silicon Dioxide (SiO2)
Mineral
Carnelian
Chalcedony (cryptocrystalline quartz), SiO2
Mineral
Rock Salt / Halite Crust
Halite (Sodium Chloride, NaCl)
sedimentary
Marble
Metamorphosed Limestone (main mineral: Calcite, CaCO3)
metamorphic
Magnetic Hematite
Magnetized Hematite (an iron oxide mineral, Fe2O3, that has undergone magnetization)
Mineral
Quartz (pebble)
Quartz (SiO₂)
Mineral
Quartzite and Chert
Silicon Dioxide (SiO2)
metamorphic and sedimentary
Quartz (vein quartz)
SiO2 (Silicon Dioxide)
Mineral
Hematite
Hematite (Fe2O3)
mineral
Quartz
SiO₂ (Silicon Dioxide)
Mineral