Starfish Fossil
Asteroidea fossil
Category
Browse sedimentary (fossilized organic matter) specimens identified by the Rock Identifier community.
Starfish Fossil
Asteroidea fossil
Fossilized tooth or tooth fragment
Indeterminate vertebrate tooth; likely mammalian, mineralized hydroxyapatite
Travertine
Calcareous Tufa / Travertine (CaCO3)
Jasper
Silicon Dioxide (Microcrystalline Quartz, $SiO_2$)
Chert (often called Flint)
Chert (Cryptocrystalline Quartz, SiO2)
Banded Chert
Chert (Silicon Dioxide, SiO2)
Fossiliferous Limestone
Biogenic Sedimentary Rock (CaCO3)
Chert (variations include Flint)
Chert (SiO2)
Ironstone Concretion (Boxwork)
Siderite-Limonite Concretion (FeO(OH)·nH2O)
Petrified Wood
Silicified Wood (SiO2)
Petrified Wood (Silicified Fossil)
Silicified Wood (SiO2)
Limestone
Sedimentary Calcium Carbonate (CaCO3)
Fossilized Solitary Rugose Coral (Horn Coral)
Rugosa (Order Rugosa)
Bituminous Coal
Coal (Organically derived sedimentary rock)
Sandstone
Arenite (primarily composed of SiO2)
Banded Calcite (Zebra Calcite)
Calcite (CaCO3) with trace organic or oxide inclusions
Shale (or Mudstone)
Siltstone/Argillite (composed mainly of clay and silt-sized particles)
Limestone with Fossil
Sedimentary limestone, calcium carbonate (CaCO3)
Coal
Bituminous coal (Complex organic sedimentary rock)
Banded Chert (River Pebble)
Microcrystalline Quartz (SiO2)
Shale with Coprolite influence
Argillaceous sedimentary rock (Shale/Mudstone)
Chert (Jasper)
Microcrystalline Quartz (SiO2) with hematite impurities
Chert (Yellow Jasper variant)
Silicon Dioxide (SiO2)
Chert (Flint Nodules)
Silicon Dioxide (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Chert
Cryptocrystalline Quartz (SiO2)
Brown Chert
Microcrystalline Quartz (SiO2)
Chert (Jasper/Flint variety)
Silicon Dioxide (SiO2)
Chert
Microcrystalline Quartz (SiO2)
Chert (and Chalcedony)
Silicon Dioxide (SiO2)
Chert (Jasper/Flint variety)
Silicon dioxide (SiO2) - Microcrystalline Quartz
Jasper
Microcrystalline Quartz (SiO2 with iron oxide impurities)
Limestone (Tufa/Travertine)
Sedimentary Calcium Carbonate (CaCO3)
Petrified Wood
Silicified Wood (SiO2)
Glauconite Sandstone
Glauconitic Sandstone (K(Fe,Al)2(Si,Al)4O10(OH)2)
Chert (Nodule)
Chert (Silicon Dioxide, SiO2)
Petrified Wood
Silicified wood (primarily SiO2)
Chert (Yellow Jasper variant)
Microcrystalline Quartz (SiO2)
Limestone
Calcium Carbonate (CaCO3)
Sandstone
Arenite (SiO2 composed primarily of quartz)
Limestone (or Calcite Pebble)
Calcium Carbonate (CaCO3)
Chert (potentially worked flint)
Cryptocrystalline microcrystalline quartz (SiO2)