Geode (unopened)
Silica-filled Concretion (SiO2)
Category
Browse sedimentary rock specimens identified by the Rock Identifier community.
Geode (unopened)
Silica-filled Concretion (SiO2)
Satin Spar (Gypsum)
Hydrous Calcium Sulfate (CaSO4·2H2O)
Chert (Common Opal/Jasper variety)
Microcrystalline Quartz (SiO2) with hydration
Quartz Druzy Geode
Silicon Dioxide (SiO2) - Crystalline Variety
Limonite Concretion
Limonite (Hydrated iron(III) oxide-hydroxides, FeO(OH)·nH2O)
Druzy Quartz Geode (likely Smokey Quartz variety)
Silicon Dioxide (SiO2) - specifically a geode formation lined with druzy quartz crystals, with a likely brownish hue indicating smokey quartz.
Liesegang Ring Siltstone
Siltstone with iron oxide Liesegang bands
Chert Nodules (Jasper)
Microcrystalline Quartz (SiO2)
Calcite on Limestone (or Fossil)
Calcium Carbonate (CaCO3)
Agatized Chert / Chalcedony
Silicon Dioxide (SiO2)
Chert Concretion / Nodule
Microcrystalline Quartz (SiO2)
Chert (often called Flint or Jasper)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Quartz Geode
Silicon Dioxide (SiO2)
Shale or Slate with Quartz Veins
Shale (fine-grained clastic sedimentary rock) or Slate (low-grade metamorphic rock formed from shale) with Quartz (SiO2) veins
Sandstone (likely Quartzose Sandstone)
Arenite (SiO2 based)
Quartz Geode
Silicon Dioxide (SiO2) in a Geode body
Ironstone Concretion / Goethite Nodules
Ironstone (composed primarily of Goethite FeO(OH) and Limonite)
Limonite-stained Chert
Silicon Dioxide (SiO2) with Hydrated Iron Oxide (FeO(OH)·nH2O)
Chert (Jasper/Agate variety)
Microcrystalline Quartz (SiO2)
Chert (Jasper variety)
Silicon Dioxide (SiO2)
Shale
Fissile Clay-dominant Mudrock (SiO2, Al2O3, K2O, Na2O, CaO, MgO)
Red Jasper
Silicon Dioxide (SiO2) with Hematite impurities
Chert (Flint)
Chert (Microcrystalline Quartz, SiO2)
Mookaite Jasper
Radiolarite (Silicified radiolarian chert), SiO2
Chert (Nodule)
Microcrystalline Silica (SiO2)
Red Jasper
Red Jasper (SiO2 with Fe2O3 impurities)
White Jade / White Chalcedony
Nephrite Jade (Ca2(Mg,Fe)5Si8O22(OH)2) or Chalcedony (SiO2)
Chert (Jasper Variant likely)
Silicon Dioxide (SiO2)
Banded Calcite (often sold as 'Mexican Onyx')
Calcite (Calcium Carbonate, CaCO3)
Kambaba Jasper
Stromatolite (Fossilized Algae)
Banded Flint (Polished Stripe Flint)
Silicon Dioxide (SiO2) - variety of Chert
Chert (Chalk-associated Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert / River Jasper
Microcrystalline Quartz (SiO2)
Quartz Calcite Vug in Limestone
Calcium Carbonate (CaCO3) with Silicon Dioxide (SiO2) inclusions
Banded Agate (Onyx variety)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Dendritic Agate (specifically Orange/Tumbled)
Silicon Dioxide (SiO2) with Oxide Inclusions
Quartzite with inclusions
Quartzite (primarily SiO2)
Chert Pebble/Nodule
Chert (a microcrystalline or cryptocrystalline sedimentary form of quartz, SiO2)
Chert (Jasper variety)
Silicon Dioxide (SiO2)
Quartz Geode
Silicon Dioxide (SiO2)
Chert (specifically Flint or Dark Chalcedony)
Silicon Dioxide (SiO2)
Granite
Phaneritic Igneous Rock (Granite)