Septarian Nodule or Mud Crack Fossil
Septarian Nodule (Concretion)
Category
Browse organic mineral specimens identified by the Rock Identifier community.
Septarian Nodule or Mud Crack Fossil
Septarian Nodule (Concretion)
Chert (Nodule)
Silicon Dioxide (SiO2)
Chert / River Jasper
Microcrystalline Quartz (SiO2)
Fossilized Shark Tooth
Scapanorhynchus (Sand Tiger Shark relative)
Red Coral
Corallium rubrum (Calcium Carbonate, CaCO3 with Carotenoid pigments)
Petrified Wood
Silicified wood (primarily Silicon Dioxide, SiO2)
Chert (Yellow Jasper/Flint)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Chert (often called Flint in this context)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (often called Flint when in chalk or limestone)
Silicon Dioxide (SiO₂)
Chert (Jasper variety)
Silicon Dioxide (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Chert (Nodule)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
River Stone (likely Mudstone or Siltstone)
Lutite (Clastic sedimentary rock composed of clay and silt-sized particles)
Graphite
Graphite (Chemical Formula: C)
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Chert (and/or Flint)
Microcrystalline Quartz (SiO2)
Chert (and Flint variant)
Chert (SiO2)
Chert (and Petrified Wood)
Silicon Dioxide (SiO2)
Chert (with Limestone/Dolomite host)
Microcrystalline Quartz (SiO2)
Moqui Marble (Shaman Stone)
Iron Oxide Concretion (composed primarily of Quartz sand with Hematite/Goethite shell)
Dinosaur Bone (Gembone)
Agatized Dinosaur Bone (Silicified Paleo-osteoid)
Fossilized Coral
Scleractinian Anthozoa (Fossilized Calcium Carbonate, CaCO3)
Petrified Wood
Silicified Wood (SiO2)
Chert (Flint Nodular)
Chert (Silicon dioxide, SiO2)
Ironstone Concretion (Ironstone Gourd)
Limonite/Goethite Concretion (FeOO(H))
Glauconitic Sandstone (Greensand)
Glauconitic Sandstone ((K, Na)(Fe3+, Al, Mg)2(Si, Al)4O10(OH)2)
Chert (Yellow Jasper/Flint)
Silicon Dioxide (SiO2)
Chert (Jasper-bearing)
Microcrystalline silica (SiO2) with iron oxide inclusions
Agatized Chert / Chalcedony
Silicon Dioxide (SiO2)
Unknown Organic Object (likely a berry or fruit)
Not applicable; this is not a geological specimen. If it were a cranberry, its scientific name would be Vaccinium macrocarpon; if a cherry, it would be Prunus avium or Prunus cerasus.
Chert (variously known as Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (specifically Banded Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (White Chert)
Silicon Dioxide (SiO2)
Chert (Yellow or Tan Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (often called Flint in this variation)
Silicon dioxide (SiO2) - Microcrystalline quartz
Petrified Wood
Silicified Wood (primarily Chalcedony/Quartz, SiO2)
Ammonite Fossil
Ammonoidea (Calcium carbonate - CaCO3)
Tufa
Calcareous Tufa (Calcium Carbonate, CaCO3)
Petrified Wood
Silicified Wood (primarily SiO2)
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony, formula: SiO2)
Petrified Wood
Silicified Wood (SiO2)
Chert (variations include Flint/Jasper)
Cryptocrystalline Quartz (SiO2)