Crinoid Stem Segment Fossil
Crinoidea (columnal ossicle)
fossil
Category
Organic Specimen (Fossil)
Browse organic specimen (fossil) specimens identified by the Rock Identifier community.
Learn about Organic Specimen (Fossil) in the encyclopedia
View all →
Orthoceras fossil in limestone
Orthoceras regulare (extinct nautiloid cephalopod)
fossil
Carved Mottled Greenish-Yellow Crystal/Glass Object
Unknown; possibly a form of quartz (chalcedony/jadeite/nephrite) or glass/resin.
Man-made Object/Uncertain Mineral
Shale with Siltstone layering
Sedimentary Clastic Rock (Mudstone/Shale)
sedimentary
Lepidodendron Fossil in Sandstone
Lepidodendron (Lycophytina, Lepidodendrales)
sedimentary
Petrified Wood (Agatized/Silicified Wood)
Silicified Wood / Chalcedony (SiO2)
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Gastropod Steinkern (Fossilized Snail Cast)
Phylum Mollusca, Class Gastropoda (Commonly CaCO3 or SiO2 after replacement)
Sedimentary
Sandstone and Conglomerate pebbles
Sedimentary clastic rock
sedimentary
Shale with Trace Fossils
Fissile mudrock (Shale)
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Murex Fossil
Muricidae (Calcium Carbonate fossilization)
fossil
Fossilized Gastropod in Limestone
Gastropoda (Class) in Calcium Carbonate (CaCO3)
sedimentary
Polished dendritic agate or jasper
Microcrystalline quartz (SiO₂), likely chalcedony with manganese-oxide dendrites
mineral
Banded sandstone pebble
Quartz-rich lithic sandstone; exact provenance and composition require testing
sedimentary
Sandstone (Ferruginous)
Arenite (Fe2O3 enriched)
sedimentary
Calamites fossil
Calamites (extinct genus of arborescent horsetails)
fossil
Red Jasper
Silicon Dioxide (SiO2) with Iron Oxide inclusions
sedimentary
Rugose Coral (Horn Coral) Fossil
Order Rugosa (likely Grewingkia or Zaphrentis genus)
fossil
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Limestone Pebble
Sedimentary Calcium Carbonate (CaCO3)
sedimentary
Brachiopod Fossil in Limestone
Phylum Brachiopoda, Class Rhynchonellata
sedimentary
Fossilized Wood (with Coal and Limonite)
Petrified Wood (Silicified or Carbonized Flora)
sedimentary
Bivalve Fossil (Clam Shell)
Class Bivalvia
fossil
Gastropod Internal Mold (Steinkern)
Class Gastropoda fossil mold (Phylum Mollusca)
sedimentary
Limestone (Flagstone)
Fossiliferous Limestone (CaCO3)
sedimentary
Chert
Microcrystalline Quartz (SiO2)
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Fossil Coral (Petoskey Stone / Rugose Coral)
Hexagonaria percarinata (or similar fossilized rugose/tabulate coral)
fossil
Shale or Argillite
Shale (sedimentary) / Argillite (metamorphic)
Sedimentary or Metamorphic (low-grade)
Sandstone (with potential trace fossils)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Fossil Shark Tooth
Otodus sp. (Eocene shark fossil)
fossil
Petrified Wood
Silicified Wood (SiO2 - primarily Quartz/Chalcedony/Opal)
Mineral/Fossil (Sedimentary context)
Fossilized Brachiopod
Phylum Brachiopoda (Calcium Carbonate/Silica replacement)
sedimentary
Sandstone (Quartzose)
Arenite (primarily SiO2)
sedimentary
Bryozoan Fossil
Phylum Bryozoa (commonly known as 'moss animals')
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Stromatolite
Biogenic sedimentary structure (Stromatolite)
fossil
Fossilized Coral (Rugose Coral / Horn Coral)
Rugosa / Scleractinia
fossil
Fossilized Coral (Rugose or Tabulate Coral)
Phylum Cnidaria, Class Anthozoa (silicified or calcified coral fossil)
fossil
Sandstone
Arenite
sedimentary
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary