Botryoidal Black Chalcedony Geode (Black Grape Agate)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Category
Browse sedimentary (alluvial deposit) specimens identified by the Rock Identifier community.
Botryoidal Black Chalcedony Geode (Black Grape Agate)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Jasper and Quartzite Pebble
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Copper-bearing Mica Schist
Mica Schist with Native Copper inclusions
Turquoise
Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]
Ferruginous Quartz
Silicon Dioxide (SiO2) with Iron Oxide (Hematite/Limonite) inclusions
Schorl (Black Tourmaline)
Sodium Iron Aluminum Borosilicate (NaFe3Al6(BO3)3Si6O18(OH)4)
Carnelian (a variety of Chalcedony)
Cryptocrystalline Quartz (SiO2) with iron oxide inclusions
Ferruginous Quartzite (Chert)
Quartzite with Iron inclusions (SiO2 + Fe2O3)
Sandstone
Arenite (SiO2 based)
Sandstone
Arenite (primarily SiO2)
Red Jasper (River Pebble)
Jasper (Silicon Dioxide, SiO2)
Belemnoit Fossil (Sea Squid Fossil)
Belemnitida (Order within Cephalopoda)
Jasper
Silicon dioxide (SiO2)
Jasper
Jasper (Silica, SiO2)
Limestone
Calcareous sedimentary rock (primarily Calcium Carbonate, CaCO3)
Yellow Jasper
Silicon Dioxide (SiO2) with Goethite/Iron Oxide inclusions
Petrified Wood
Silicified wood (principally Silicon Dioxide, SiO2)
Septarian Nodule (Thunder Egg)
Septarian Concretion (CaCO3 + CaMg(CO3)2 + SiO2)
Sandstone (with Iron Staining)
Clastic Sedimentary Rock (primarily Quartz, SiO2)
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (primarily SiO2)
Blue Calcite
Calcium Carbonate (CaCO3)
Yellow Calcite
Calcite (Calcium Carbonate, CaCO3)
Hematite
Iron (III) Oxide, Fe2O3
Agate
Agate (Microcrystalline Quartz, SiO2)
Agate Geode with Quartz Druzy
Chalcedony (SiO2) and Quartz (SiO2)
Desert Rose
Gypsum (CaSO4·2H2O) or Baryte (BaSO4) with trapped sand grains
Orange Calcite
Calcium Carbonate (CaCO3)
Quartz Geode
Silicon Dioxide (SiO2)
Yellow Jasper
Chalcedony (Silicon Dioxide, SiO2)
Red Jasper (River-worn Pebble)
Silicon Dioxide (SiO2) with Ferric Iron inclusions
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
Emerald
Beryl (Be3Al2(SiO3)6) with Chromium and/or Vanadium impurities
Celestite (Celestine)
Strontium sulfate (SrSO4)
Fossilized Sand Tiger Shark Tooth
Carcharias taurus / Striatolamia macrota (mineralized as Hydroxylapatite/Francolite)
Banded Agate
Chalcedony (Silicon Dioxide, SiO2)
Sandstone Concretion
Moqui Marble / Iron-oxide Concretion (SiO2 with Hematite/Goethite)
Garnet (Almandine or Spessartine likely)
Garnet Group Minerals (e.g., Almandine Fe3Al2(SiO4)3, Pyrope Mg3Al2(SiO4)3, Spessartine Mn3Al2(SiO4)3)
Diamond
Carbon (C), specifically in an isometric crystal system.
Peridot (likely, given the color and bead form)
Olivine, variety Peridot (Mg,Fe)2SiO4
Quartz (River Pebble)
Quartz (SiO₂ - Silicon Dioxide)
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)