Geode with Iron-Stained Quartz/Calcite
Silicon Dioxide (SiO2) or Calcium Carbonate (CaCO3) in Sedimentary Matrix
Category
Browse sedimentary rock or mineral (depending on origin and purity) specimens identified by the Rock Identifier community.
Geode with Iron-Stained Quartz/Calcite
Silicon Dioxide (SiO2) or Calcium Carbonate (CaCO3) in Sedimentary Matrix
Ferruginous Quartz
Silicon Dioxide (SiO2) with Iron Oxide inclusions
Seashell Fossil
Invertebrate fossil (phylum Mollusca)
Quartzite
Quartzite (primarily SiO2)
Folded Schist / Gneiss (Metamorphic Rock)
Regional Metaphoric Folded Outcrop (predominantly Schist/Gneiss)
Diamond (in a gold setting)
Carbon (C)
Banded Calcite (Green Onyx)
Calcium Carbonate (CaCO3)
Fossilized Bone
Petrified Bone / Biogenic Sedimentary
Hag Stone
Perforated Flint or Chert
Fossiliferous Shale
Fossiliferous Mudstone / Shale
River Rock
Silica-rich water-worn rock
Granite
Intrusive Igneous Rock
Porphyritic Basalt
Porphyritic Basalt with Plagioclase Phenocrysts
Red Sandstone
Arenite (primarily Quartz with Hematite cement)
Conglomerate
Conglomerate rock
Turquoise in Matrix
Hydrous phosphate of copper and aluminium, CuAl6(PO4)4(OH)8·4H2O
Schist
Schist (various mineralogical compositions including mica, chlorite, talc, etc.)
Sandstone (Ferruginous/Banded)
Clastic Terrigenous Sandstone (SiO2 with Fe2O3 cement)
Sandstone
Arenite (SiO2 dominated sandstone)
Quartz-rich pegmatite or quartz vein rock
Mostly quartz (SiO₂), with probable feldspar and iron-oxide staining
Concretion
Siderite or Ironstone Concretion
Sandstone (specifically Arkose or Ferruginous Sandstone)
Sandstone (SiO2 predominant)
Amethyst
Amethyst (Silicon Dioxide - SiO2 with iron impurities)
Sandstone
Arenite (primarily SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Chalcedony (Quartz Nodule)
Silicon Dioxide (SiO2)
Sandstone (likely Quartzose)
Arenite (primarily SiO2)
Bull Quartz (White Quartz)
Silicon Dioxide (SiO2)
Sandstone (Pebble)
Sandstone (SiO2 dominated with minor feldspar/clay)
Tumbled brown mineral pebble, possibly jasper or weathered quartzite
Indeterminate from the blurred image; likely microcrystalline quartz (SiO₂) if jasper, or quartzite dominated by quartz
Quartz-rich rock, likely milky quartz or quartzite
Quartz (SiO₂), possibly quartzite if metamorphically recrystallized
Granite
Intrusive Igneous Rock
Druzy Quartz on Host Rock
Silicon Dioxide (SiO2) with various iron-oxide inclusions
Gold Nugget
Native Gold (Au)
Gold Nugget
Native Gold (Au)
Quartz Geode (Cracked)
Crystalline Silicon Dioxide (SiO2)
Quartz (Milky/Common Quartz)
Silicon Dioxide (SiO2)
Turquoise and Red Coral
Turquoise: CuAl6(PO4)4(OH)8·4H2O; Red Coral: Corallium rubrum (organic gemstone)
Quartz Pebble (Chalcedony/Agate variety)
Silicon Dioxide (SiO2)
White quartz-rich pebble
Likely quartzite or milky-quartz pebble (SiO₂)
Conglomerate
Conglomerate (clastic sedimentary rock)
Porphyritic Basalt or Porphyritic Andesite
Porphyritic Extrusive Igneous Rock