Slate
Slate (a fine-grained, foliated metamorphic rock). Mineral composition: Primarily composed of mica minerals (muscovite, chlorite, sericite) and quartz, with minor amounts of hematite, pyrite, and other accessory minerals.
sedimentary
Category
Sedimentary (Fossilized Organic Matter)
Browse sedimentary (fossilized organic matter) specimens identified by the Rock Identifier community.
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Fossil-bearing Sedimentary Rock
Sedimentum cum fossili
fossil
Fossil shell fragment (likely brachiopod or bivalve)
Indeterminate fossilized carbonate shell; likely Brachiopoda or Bivalvia
fossil
Amber
Succinite (C10H16O)
mineraloid
Mother of Pearl (Nacre) / Shell Fragment
Biogenic Calcium Carbonate (Aragonite and Conchiolin)
fossil
Limestone Pebble with Crinoid Fossil
Calcium Carbonate (CaCO3) - Fossiliferous Limestone
sedimentary
Concretion
Various mineral compositions, typically carbonate or iron oxide cemented sediment
Sedimentary
Petoskey Stone
Hexagonaria percarinata
fossil
Fossilized Oyster Shell
Ostrea / Exogyra (Phylum Mollusca)
fossil
Coal (likely Bituminous or Lignite)
Organic Sedimentary Rock (Carbonaceous)
sedimentary
Possible weathered quartz-rich rock or iron-stained mineral fragment
Indeterminate; possibly quartz (SiO₂) with iron-oxide inclusions
mineral
Fossilized Coral (Petoskey Stone type)
Hexagonaria percarinata (Fossilized Rugose Coral)
fossil
Banded Agate
Cryptocrystalline variety of Quartz (SiO2)
mineral
Dendritic Agate
Silicon Dioxide (SiO2) with Manganese/Iron oxide inclusions
mineral
Amygdaloidal Basalt with Quartz/Zeolite Infill
Amygdaloidal Basalt (extrusive volcanic rock with SiO2 or CaAl2Si3O10·3H2O infill)
igneous
Fossiliferous Limestone
Bioclastic Limestone (CaCO3)
sedimentary
Sedimentary Rock with Crafts (Pet Rock)
Sedimentary rock decorated with synthetic materials
sedimentary
Orthoceras Fossil in Limestone
Orthoceras (extinct genus of cephalopods), mineralized as Calcite (CaCO3) in Fossiliferous Limestone
sedimentary
Polished amber
Amber (fossilized plant resin; chiefly polymerized diterpenoid resin)
gemstone
Chert / Flint
Microcrystalline Quartz (SiO2)
sedimentary
Petoskey Stone
Hexagonaria percarinata
fossil
Baltic Amber (Raw)
Succinite
fossil
Ammolite
Biogenic gemstone (Aragonite, CaCO3)
mineral
Fossiliferous Sedimentary Rock
Sedimentary Rock with Invertebrate Fossil Imprint
fossil
Jasper
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Yellow Jasper)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Flint)
Silicon Dioxide (SiO2)
sedimentary
Jasper
Silicon dioxide (SiO2)
sedimentary
Chert (Flint nodule)
Chert (SiO2)
sedimentary
Moss Agate
Chalcedony (Silicon Dioxide) with Chlorite or Iron/Manganese inclusions (SiO2)
mineral
Fulgarite
Fulgurite (Lechatelierite / Vitrified Sand)
igneous
Fossil Coral
Hexagonaria or Rugose coral fossil in limestone/silica matrix
fossil
Crinoid Stem Fossil
Crinoid Columnal (Phylum Echinodermata)
fossil
Limestone Pebble
Sedimentary Calcium Carbonate (CaCO3)
sedimentary
Fossil Shark Tooth
Carcharhinidae or Lamniformes sp. (possibly Carcharodon or Otodus genus)
fossil
Shark Tooth Fossil
Lamniformes (Shark tooth fossil composed of Fluorapatite)
fossil
Fossil shell fragment
Likely a fossilized brachiopod or bivalve; exact taxon cannot be determined from the image
fossil
Limestone or Sandstone Cobble
Sedimentary rock (Calcium carbonate or Quartz based)
sedimentary
Fossiliferous Limestone with Brachiopods
Calcium Carbonate (CaCO3) with fossilized Brachiopoda sp. (likely Order Spiriferida or Rhynchonellida)
sedimentary
Petoskey Stone / Fossilized Coral
Hexagonaria percarinata
fossil
Fulgurite
Fulgurite (Lechatelierite / Vitreous Silica)
mineral
Tree Agate
Silicon Dioxide (SiO2) with Dendritic Inclusions
gemstone