River Stone (Basalt or Siltstone with banding)
Polished Basaltic or Siliciclastic River Cobble
Category
Browse sedimentary (silicified fossiliferous chalcedony) specimens identified by the Rock Identifier community.
River Stone (Basalt or Siltstone with banding)
Polished Basaltic or Siliciclastic River Cobble
Chert (often called Flint or Jasper when pigmented)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Chert (Black Chert / Flint)
Silicon Dioxide (SiO2)
Calcite
Calcium Carbonate (CaCO3)
Chert / Flint
Chert (Microcrystalline Quartz, SiO2)
Ferruginous Chert
Silicon dioxide with iron oxide impurities (SiO2 + Fe2O3)
Quartzite River Stone
Metamorphosed Quartz-rich Sandstone (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Pyrite with Limonite/Goethite Alteration (Pseudomorph)
Iron Sulfide (FeS2) transitioning to Hydrated Iron Oxides (FeO(OH)·nH2O)
Yellow Ochre / Limonite
Limonite (FeO(OH)·nH2O)
Quartzite
Quartzite (primarily SiO2)
Quartz (Milky or Cloudy Quartz)
Silicon Dioxide (SiO2)
Precious Opal
Hydrated Silica (SiO2·nH2O)
Quartzite (or Iron-Stained Quartz Pebble)
Silicon Dioxide (SiO2) with Ferric Oxide inclusions
Goethite (Iron Ore)
Goethite (FeO(OH))
Limonite (Iron Ore)
Limonite (Hydrous iron(III) oxide-hydroxide mixture, primarily FeO(OH)·nH2O)
Red Jasper
Silicon Dioxide (SiO2) with iron oxide impurities
Quartz Geode (Citrine or Iron-stained Quartz)
Silicon Dioxide (SiO2)
White Marble
Recrystallized Calcite (CaCO3)
Jasper
Silicon dioxide (SiO2)
Siltstone
Siltstone (primarily composed of SiO2 with various clay minerals)
Chert (varietal: Jasper or Flint)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
Chert (Cherty Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Flint)
Chert (SiO2)
Banded Chert or Agate
Silicon Dioxide (SiO2)
Chert (Iron-stained)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (specifically Yellow Jasper/Flint)
Microcrystalline Quartz (SiO2)
Sandstone
Arenite
Chert (specifically Flint or Jasper variant)
Microcrystalline silica (SiO2)
Ironstone (with Limonite/Goethite)
Ferruginous Sedimentary Rock (contains Limonite FeO(OH)·nH2O and Hematite Fe2O3)
Red Sandstone
Arenite (with Iron Oxide / Hematite cementation)
Banded Chert (Agate-like Flint)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Ferruginous Sandstone (Ironstone)
Sandstone with Hematite/Goethite cement (SiO2 + FeO(OH))
Chert (and/or River Pebble)
Microcrystalline silica (SiO2)
Sandstone
Arenite (primarily SiO2, silica)
Siltstone
Siltstone (primarily composed of SiO2)
Limestone
Calcium Carbonate (CaCO3)
Sandstone (Water-worn Cobble)
Arenite (variable composition, primarily SiO2)
Sandstone (Ferruginous)
Arenite (Fe2O3 enriched)
André's Landing Rock (Sandstone Boulder)
Newark Supergroup Sandstone (likely Stockton Formation)
Chert (Jasper/Agate variety)
Cryptocrystalline Quartz (SiO2)