Agate Geode
Silicon Dioxide (SiO2) - Banded Chalcedony
Category
Browse sedimentary (alluvial deposit) specimens identified by the Rock Identifier community.
Agate Geode
Silicon Dioxide (SiO2) - Banded Chalcedony
Pyrite
Iron Sulfide (FeS2)
Pyrite
Iron Disulfide (FeS2)
Banded Calcite (often sold as 'Travertine' or 'Mexican Onyx')
Calcium Carbonate (CaCO3)
Flesh-toned Siltstone
Siltstone (composed of microscopic Quartz and Feldspar grains)
Black Veined Jasper (Spiderweb Jasper)
Silicon Dioxide (SiO2)
Coquina
Bioclastic Limestone (composed primarily of CaCO3)
Septarian Nodule (Dragon Stone)
Septarian Concretion (CaCO3 - Calcite, Aragonite, and Limestone/Clay)
Chert (Jasper-like)
SiO2 (Cryptocrystalline Quartz)
Banded Gneiss
Gneiss (High-grade Metamorphic Rock)
Septarian Nodule
Septarian Concretion (CaCO3 with Siderite/Calcite/Aragonite)
Red Sandstone
Arenite (primarily Quartz with Hematite cement)
Jasper pebble
Jasper (Silicon Dioxide, SiO2)
Travertine
Travertine (CaCO3 - Calcium Carbonate)
Amethyst with Marcasite accents
Amethyst (Silicon Dioxide SiO2) and Marcasite (Iron Sulfide FeS2)
Quartz
Silicon Dioxide (SiO2)
Chert (Brown variety)
Silicon Dioxide (SiO2)
Agate (various color varieties)
SiO₂ (Silicon Dioxide)
Glacial Erratic (Sandstone/Quartzite)
Glacial Erratic specimen (likely Orthoquartzite or Feldspathic Sandstone)
Banded Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
Chert (Nodule / Geode fragment)
Microcrystalline Quartz (SiO2)
Red Jasper
Silicon dioxide (microcrystalline quartz with iron oxide inclusions), SiO2
Coal (most likely Bituminous or Anthracite)
Coal (organic sedimentary rock)
Banded Iron Formation (BIF)
Banded Iron Formation (composed primarily of Hematite [Fe2O3], Magnetite [Fe3O4], and Chert [SiO2])
Rough Emerald
Beryl (Be3Al2Si6O18 with Chromium/Vanadium impurities)
Jasper (specifically Bloodstone or Heliotrope variety)
Silicon Dioxide (SiO2) with iron oxide inclusions
Wishing Stone (Basalt/Greywacke with Quartz Vein)
Basalt or Siltstone with SiO2 (Quartz) hydrothermal intrusion
Carnelian (a variety of Chalcedony)
Silicon Dioxide (SiO2) with iron oxide impurities
Petoskey Stone
Hexagonaria percarinata (Fossilized Rugose Coral)
Banded Gneiss
Gneiss (High-grade regional metamorphic rock)
Almandine Garnet
Almandine (Fe3Al2(SiO4)3)
Pyrite
Iron Sulfide (FeS2)
Clear Quartz
Silicon Dioxide (SiO2)
Sulfur
Native Sulfur (S8)
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
Limestone
Calcium Carbonate (CaCO3)
Pyrite
Iron Disulfide (FeS2)
Red Sandstone
Arenite (with Iron Oxide / Hematite cementation)
Pebble or Cobble (likely composed of sandstone or conglomerate)
Clastic Sedimentary Rock (specific name like sandstone, conglomerate, or breccia would require microscopic analysis of clast size and angularity)
Turquoise (likely Stabilized or Dyed Howlite/Magnesite)
Hydrated phosphate of copper and aluminium - CuAl6(PO4)4(OH)8·4H2O
Chert
Chert (variant of microcrystalline quartz)
Jasper pebble
Silicon dioxide (SiO2) with iron oxide inclusions