Tiger's Eye
Titanium-containing Quartz (Silica: SiO2)
Mineral
Category
Sedimentary (Fossilized Organic Matter)
Browse sedimentary (fossilized organic matter) specimens identified by the Rock Identifier community.
Chondrite Meteorite
L or H Ordinary Chondrite
igneous
Fossilized Sea Urchin (Echinoid)
Echinoidea (Class); commonly Clypeasteroida for sand dollar types
sedimentary (fossil)
Pearl
Aragonite (CaCO3) with Conchiolin
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
Anthracite Coal
Anthracite (a form of coal, primarily carbon)
sedimentary
Dendritic Rhodonite
Rhodonite (Manganese Silicate), (Mn,Fe,Mg,Ca)SiO3
mineral
Montana Moss Agate
Chalcedony (Silicon Dioxide, SiO2)
mineral
Ammolite
Biogenic gemstone (Aragonite, CaCO3)
mineral
Concretion
Various mineral compositions, typically carbonate or iron oxide cemented sediment
Sedimentary
Slag
Ferrous Slag (Amorphous calcium-magnesium-aluminum silicates)
igneous (artificial/anthropogenic)
Dendritic Quartz
Silicon Dioxide (SiO2) with Manganese/Iron oxide inclusions
mineral
Orthoceras Fossil in Limestone
Orthoceras (extinct genus of cephalopods), mineralized as Calcite (CaCO3) in Fossiliferous Limestone
sedimentary
Cockle Shell (Fossil or Recent)
Class Bivalvia, Family Cardiidae (e.g., Cerastoderma edule for common cockle)
Sedimentary (Biogenic, a type of fossil)
Fossilized Shark Tooth (Dermal Denticle or worn tooth fragment)
Elasmobranchii (fossil remains)
sedimentary
Fossiliferous Limestone with Rugose Coral
Calcite (CaCO3) matrix containing Rugosa (order of extinct solitary and colonial corals)
sedimentary
Fossiliferous Limestone with Brachiopods
Calcium Carbonate (CaCO3) with fossilized Brachiopoda sp. (likely Order Spiriferida or Rhynchonellida)
sedimentary
Crinoid Stem Fossil
Class Crinoidea (Phylum Echinodermata), primarily Calcium Carbonate (CaCO3)
sedimentary
Ammonite Fossil (Polished Half / Cleoniceras)
Ammonoidea (Subclass), often Cleoniceras genus; fossilized with Calcite (CaCO3) and Aragonite
Sedimentary
Coal (likely Bituminous or Lignite)
Organic Sedimentary Rock (Carbonaceous)
sedimentary
Dendritic Opal
Hydrated Silica (SiO2·nH2O) with Manganese or Iron Oxide inclusions
mineral
Fossilized Shark Tooth (Otodus obliquus)
Otodus obliquus (composed primarily of Fluorapatite)
mineral
Chert (Chert Nodule with Chalky Cortex)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Atlantic Calico Scallop (Biogenic Aragonite/Calcite)
Argopecten gibbus (Chemical: CaCO3)
mineral
Bamboo Leaf Jasper
Silicified Siltstone or Jasper (SiO2)
sedimentary
Fossilized Shark Tooth (Otodus obliquus)
Otodus obliquus (Mineral composition: Bio-apatite/Calcium Phosphate replaced by various minerals)
sedimentary (fossil)
Shungite
Non-crystalline carbon (allotrope of carbon)
metamorphic
Jasper
Jasper (Silicon Dioxide, SiO2)
sedimentary
Dendritic Agate (Tumbled)
Silicon Dioxide (SiO2) with inclusions
mineral
Dendritic Opal (Merlinite)
Hydrated Silica with Manganese/Iron oxide inclusions (SiO2·nH2O)
mineral
Fossilized Rugose Coral (Horn Coral)
Order Rugosa (extinct tetra-coral)
sedimentary
Pink Orthoclase Feldspar with Dendrites
Orthoclase (KAlSi3O8) with Manganese Oxide dendrites
mineral
Dendritic Opal
Opalized Chalcedony with Manganese Inclusions (SiO2 · nH2O)
mineral
Sandstone Concretion with Fossil Wood
Ferruginous Sandstone Concretion (SiO2 with Fe2O3 cement)
sedimentary
Anthracite Coal
Anthracite (a variety of coal, predominantly carbon)
Sedimentary Rock (Metamorphosed)
Fish Fossil in Limestone
Lycoptera (likely) in Micritic Limestone
sedimentary
Anthracite Coal
Anthracite C
metamorphic
Chert (or Chalcedony)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Flint)
Microcrystalline silica (SiO2)
sedimentary
Pyrite (Fool's Gold) Cube
Iron Sulfide (FeS2)
mineral
Flint (Chert)
Silicon Dioxide (SiO2)
sedimentary