Chert (specifically a weathered Chert nodule or fragment)
Chert; Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Category
Igneous And Metamorphic Derivative (Weathered)
Browse igneous and metamorphic derivative (weathered) specimens identified by the Rock Identifier community.
Schist
Schist (various mineralogical compositions including mica, chlorite, talc, etc.)
Metamorphic
Banded Rock (likely Quartz-rich)
Uncertain, likely a Metamorphic Rock (e.g., Gneiss or Schist) with prominent Quartz and other minerals
Mineral
Greenstone / Glauconitic Siltstone
Metabasalt or Glauconite-rich Sedimentary Rock
metamorphic or sedimentary
Yellow Ocher / Limonite
FeO(OH)·nH2O (Hydrated iron(III) oxide-hydroxide)
mineral
Aquamarine
Beryl (Be3Al2Si6O18)
Mineral
Quartz Crystal
Quartz (SiO₂)
Mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Citrine
Citrine (Silicon Dioxide - SiO2)
mineral
Quartz (Milky/Gravel variety)
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Quartz Druzy Geode
Silicon Dioxide (SiO2) - Crystalline Variety
mineral
Chert (Chert Nodule with Cortex)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Flint Pebbles)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Quartz Vein in Host Rock (Breccia/Rhyolite)
Silicon Dioxide (SiO2) with matrix
Mineral in Igneous/Sedimentary host
Amethyst (Tumbled/Weathered Quartz)
Amethyst (SiO2 with iron impurities)
mineral
Chert (Lightly weathered variety)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Sandstone (likely Ferruginous)
Arenite (SiO2 with iron oxide impurities)
sedimentary
Chert (Nodule)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Sandstone with Quartz Veining
Clastic sedimentary rock (SiO2 dominated)
sedimentary
Turquoise
Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)
mineral
Gold Ore in Quartz/Schist
Auriferous Quartz and Sulfide-bearing Schist
Metamorphic/Igneous (Hydrothermal)
Bauxite (Concretionary)
Bauxite (Al(OH)3, AlO(OH))
sedimentary
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
mineral
Amethyst
Quartz (Silicon Dioxide, SiO2) with iron impurities
mineral
Smoky Quartz
Silicon Dioxide (SiO2)
mineral
Pink Stained Rock (Likely Quartzite or Sandstone with Iron Oxide Staining)
Quartzite (metamorphic) or Sandstone (sedimentary); coloration likely due to hematite or other iron oxides.
Metamorphic or Sedimentary (with staining)
Beryl (Variety Mix)
Be3Al2(Si6O18)
Mineral
Chrysoprase
Chalcedony (Silicon Dioxide, SiO2)
mineral
Agate (or Banded Agate)
Agate (a variety of Chalcedony, which is a cryptocrystalline form of Quartz); Chemical Formula: SiO₂ (Silicon Dioxide)
Mineral, specifically a Cryptocrystalline Quartz variety
Ruby in Zoisite
Ruby (Corundum, Al2O3) in Zoisite (Calcium aluminum silicate hydroxide, Ca2Al3(SiO4)3(OH)) with some Hornblende
Metamorphic Rock (specifically a rock composed of minerals)
Quartz with Iron Stains
Quartz (SiO2) with iron oxide/hydroxide staining
Mineral
River Jasper (Green Jasper)
Silicon Dioxide (SiO2) with impurities
sedimentary
Sandstone Concretion
Sedimentary concretion
Sedimentary
Red Garnet
Garnet Group (e.g., Pyrope, Almandine, Spessartine, Grossular, Andradite, Uvarovite)
Mineral
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
mineral
Pyrite
Iron Sulfide (FeS2)
mineral
Milky Quartz with Iron Staining
Silicon Dioxide (SiO2)
mineral
Quartz Crystal Cluster
Silicon Dioxide (SiO2)
mineral
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
mineral
Ironstone Concretion (likely)
Goethite/Hematite/Limonite cemented sediment
Sedimentary Rock
Limonite (Iron Ore)
Limonite (an FeO(OH)·nH2O mineraloid, not a true mineral due to variable composition)
Mineral