Petoskey Stone
Hexagonaria percarinata (Calcite / CaCO3)
fossil
Category
Organic (Paper And Cellulose)
Browse organic (paper and cellulose) specimens identified by the Rock Identifier community.
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Chert (Arrowhead Fragment)
Silicon Dioxide (SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Chert (Jasper-bearing)
Microcrystalline silica (SiO2) with iron oxide inclusions
sedimentary
Glauconitic Sandstone (Greensand)
Glauconitic quartz wacke or arenite
sedimentary
Chert (Jasper type)
Microcrystalline Quartz (SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Black Marble
Recrystallized Limestone (CaCO3)
metamorphic
Septarian Nodule (Dragon Stone)
Septarian concretion (composition: CaCO3 - Calcite, Aragonite, and Siderite/Limestone)
sedimentary
Petrified Wood
Silicified Wood (primarily SiO2)
sedimentary
Red Jasper Concretion
Cryptocrystalline Quartz (SiO2)
sedimentary
Chert Nodule
Microcrystalline Silica (SiO2)
sedimentary
Pearl
Calcium Carbonate (Aragonite/Calcite mixed with Conchiolin), CaCO3
mineral
Fossil Shark Tooth (Otodus obliquus)
Otodus obliquus; hydroxyapatite (mineralized form Ca5(PO4)3(OH))
sedimentary (fossiliferous)
Petrified Wood
Silicified Wood (SiO2)
fossil
Chert
Chert (SiO2)
sedimentary
Petrified Wood
Silicified Wood (primarily Quartz/SiO2)
mineral
River Jasper (Chert/Chalcedony)
Silicon Dioxide (SiO2) with iron oxide impurities
sedimentary
Chert
Sedimentary Cryptocrystalline Quartz (SiO2)
sedimentary
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony, formula SiO2)
mineral
Chert with Iron Staining
Microcrystalline Quartz (SiO2)
sedimentary
Pitted Limestone
Calcium Carbonate (CaCO3)
sedimentary
Fossilized Bivalve Shell (Fossilized Clam)
Bivalvia (class) / CaCO3 (Calcium Carbonate)
fossil
Fossiliferous Limestone with Fossil Fragment
Fossiliferous Limestone (CaCO3 with organic remains)
fossil
Bivalve Fossil (Fossilized Shell)
Class Bivalvia (fossilized in Calcium Carbonate/Aragonite)
fossil
Ironstone Concretion (Moqui Marble / Boji Stone)
Sedimentary Iron Oxide Concretion (Fe2O3 / FeO(OH))
sedimentary
Fossilized Brachiopod
Brachiopoda (e.g., Atrypa or Rhynchonellida)
fossil
Sand Tiger Shark Tooth Fossil
Carcharias taurus (fossilized tooth)
fossil
Chert (Arrowhead/Projectile Point)
Chert (Cryptocrystalline Quartz, SiO2)
sedimentary
Petrified Wood
Silicified Wood (primarily SiO2)
fossil
Chert Arrowhead (Projectile Point)
Microcrystalline Quartz (Chert/Flint)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Petrified Wood
Silicified Wood (primarily Chalcedony or Quartz, SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony, formula: SiO2)
sedimentary
River Stone (Limestone)
Sedimentary Calcium Carbonate (CaCO3)
sedimentary
Chert (Nodule)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (River Pebble/Finger Stone)
Microcrystalline quartz (SiO2)
sedimentary
Chert (River Pebble)
Silicon Dioxide (SiO2)
sedimentary
Petrified Wood
Silicified wood (Quartz/Chalcedony replacement)
fossil
Chert (Arrowhead Fragment)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Jasper)
Microcrystalline Quartz (SiO2)
sedimentary