Glauconitic Sandstone
Glauconitic Quartz Sandstone (K(Fe,Al)2(Si,Al)4O10(OH)2)
Category
Browse organic materia (not a rock or mineral) specimens identified by the Rock Identifier community.
Glauconitic Sandstone
Glauconitic Quartz Sandstone (K(Fe,Al)2(Si,Al)4O10(OH)2)
Sandstone
Sandstone (principally SiO2/Silicon Dioxide)
Shark Tooth Fossil
Vertebrate fossilized tooth (various genera such as Carcharodon, Otodus, or Negaprion)
Petrified Wood
Silicified Wood (SiO2)
Moss Agate
Chalcedony (SiO2) with inclusions of hornblende or chlorite
Red Jasper with Quartz
Microcrystalline Quartz (SiO2)
Chalcedony
Cryptocrystalline Quartz (SiO2)
Fossilized Bone Fragment
Permineralized Vertebrate Fossil (Hydroxyapatite replaced by Minerals)
Glauconitic Sandstone
Glauconitic Sandstone (contains (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2)
Shale fragment
Shale (Laminated Mudstone)
Manganese Dendrite on Siltstone
Manganese Oxide (pyrolusite or psilomelane) Dendrites
Shale
Fissile mudrock (composed primarily of clay minerals and quartz)
Fossilized tooth, likely a mammalian tooth fragment
Indeterminate fossil tooth; possibly an ungulate or carnivoran tooth
Weathered River Rock (likely Chert or Basalt with algae)
Silicon dioxide (SiO2) with organic biofilm
Pearls
Pearl: biomineralized aragonite (CaCO₃) and conchiolin
Chert with Calcite Veins
Silicon Dioxide (SiO2) with Calcium Carbonate (CaCO3) intrusions
Travertine (Tufa)
Chemical Sedimentary Rock (CaCO3)
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony, SiO2)
Moss Agate (Crescent Moon Shape)
Silicon Dioxide (SiO2) with iron/manganese inclusions
Amber (Copal)
Succinite (fossilized resin)
Coal
Coal (Sedimentary Rock / Organic Rock)
Fossil Shark Tooth
Selachii (fossilized dentition)
Shale
Shale (comprised mostly of clay minerals and quartz)
Concrete or asphalt-like aggregate surface with a dark fragment
Uncertain; likely artificial concrete containing mixed lithic aggregate, not a natural rock
Jasper
Silicon dioxide (SiO2)
Tufa Rock and Tumbled Gemstones
Calcareous Tufa (Calcium Carbonate, CaCO3)
Moss Agate
Chalcedony (Silicon Dioxide / SiO2)
Petrified Wood
Silicified Wood (mainly Quartz/Chalcedony, SiO2)
Sandstone (likely Fossiliferous Sandstone)
Clastic sedimentary rock (primarily SiO2)
Sandstone with Quartz Crystal Infill
Quartz-cemented quartz arenite
Concretion
Septarian or Siderite Concretion
Moss Agate with Jasper
Chalcedony (SiO2 with inclusions)
Graphite-rich metamorphic rock (graphitic schist)
Graphitic schist; chiefly graphite (C), quartz (SiO₂), and mica minerals
Fossiliferous Limestone (Coquina)
Calcite (CaCO3) with Bioclastic inclusions
Moss Agate / Chalcedony
Silicon Dioxide (SiO2)
Weathered fossil fragment, possibly bone
Indeterminate fossilized bone; likely mineralized vertebrate bone (apatite-rich)
Moss Agate
Chalcedony (SiO2) with inclusions of manganese or iron oxides
Unidentified Dark Mineral or Rock
Indeterminate (Likely Silicon Dioxide or Carbon-based)
Geode (Unopened)
SiO2 (Quartz-filled Sedimentary Nodule)
Geode (unopened)
Chert / Chalcedony Geode (SiO2)
Fossilized Coprolite
Coprolite (fossilized feces)
Chert Nodule / Ironstone Concretion
Microcrystalline Quartz (SiO2) with Iron Oxides