Calamites Fossil (Horsetail Stem)
Calamites (Genus), part of the class Equisetopsida
sedimentary
Category
Not A Geological Specimen
Browse not a geological specimen specimens identified by the Rock Identifier community.
Dog (Sleeping)
Canis familiaris (or Canis lupus familiaris)
Organic/Biological
Fossil Coral
Cnidaria Anthozoa (Fossilized)
sedimentary
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony, formula: SiO2)
sedimentary
Chert with Asphaltum (or Tar)
Silica (SiO2) with natural Bitumen/Asphaltum
sedimentary
Basalt Column Section
Columnar Basalt (Mafic Extrusive Igneous Rock)
igneous
Septarian Nodule (Septarian Stone)
Septarian Concretion (CaCO3 with Siderite/Calcite/Aragonite)
sedimentary
Fossilized Coral
Scleractinia (fossil order), primarily Calcium Carbonate (CaCO3)
sedimentary
Fossilized Coral
Cnidaria (Anthozoa), often replaced by Calcium Carbonate (CaCO3) or Silica (SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Fossil Coral (Petoskey Stone / Rugose Coral)
Hexagonaria percarinata (Order: Rugosa, Fossilized Calcium Carbonate CaCO3)
sedimentary
Agatized Fossil (Druzy Agate)
Silicon Dioxide (SiO2) replacing organic matter
sedimentary
Gold Ore (in Quartz/Sulfide matrix)
Native Gold (Au) in Quartz (SiO2) and Pyrite (FeS2)
mineral
Petrified Wood
Silicified wood (principally Silicon Dioxide, SiO2)
sedimentary
Petrified Wood
Silicified wood (Quartz variant, SiO2)
sedimentary
Sandstone (with differential weathering)
Arenite / Quartz Sandstone (SiO2)
sedimentary
Pyrite in Shale
Iron Sulfide (FeS2) in Argillaceous Shale
sedimentary
Quartzite (Lithic Artifact)
Quartzite (SiO2)
metamorphic
Chert (Arrowhead/Tool variety)
Microcrystalline Quartz (SiO2)
sedimentary
Quartzite Pebble
Metamorphosed Sandstone (SiO2)
metamorphic
Petrified Wood
Silicified Wood / Chalcedony (SiO2)
mineral
Fossiliferous Limestone with Rugose Coral
Calcite (CaCO3) containing a Rugosa (Horn Coral) fossil
sedimentary
Fossilized Coral (Petoskey-like or Favosites)
Anthozoa (Fossilized Coral)
sedimentary
Quartz Geode / Druzy Quartz
Silicon Dioxide (SiO2)
mineral
Banded Agate (Agatized Geode Slice)
Silicon Dioxide (SiO₂)
mineral
Quartz Geode (Nodule)
Silicon Dioxide (SiO2)
sedimentary or igneous
Gold Ore
Auriferous Quartz and Sulfide Mineralization in Host Rock
igneous
Petrified Wood
Silicified Wood (SiO2)
metamorphic
Septarian Nodule or Mud Crack Fossil
Septarian Nodule (Concretion)
sedimentary
Kambaba Jasper (Crocodile Jasper)
Stromatolite (Fossilized Algae within Microcrystalline Quartz), SiO2
sedimentary
Amethyst Geode
Silicon Dioxide with trace inclusions of Iron (SiO2)
mineral
Oolitic Ironstone
Sedimentary Ooidal Ironstone (Limonite/Hematite mixture)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Ring with an Orange Inlay
N/A (Man-made object)
Man-made Object (Ring)
Petrified Wood
Silicified Wood (SiO2 permineralization)
sedimentary
Septarian Nodule (Dragon Stone)
Septarian Nodule (Calcium Carbonate/Aragonite/Calcite Concretion)
sedimentary
Limonite (Yellow Ochre)
Hydrated iron(III) oxide-hydroxide (FeO(OH)·nH2O)
mineral
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Devil's Toenail
Gryphaea (extinct genus of foam oysters, typically composed of Calcite CaCO3)
sedimentary
Limonite and Goethite encrusted Chert/Ironstone
Hydrated Iron Oxide (FeO(OH)·nH2O) with cryptocrystalline Silica (SiO2)
sedimentary
Artificial Rock Face (Faux Rock)
Glass Fiber Reinforced Concrete (GFRC)
man-made/construction material
Fulgurite
Fulgurite (Lechatelierite-rich fused silica)
mineraloid / sedimentary (secondary formation)