Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
Category
Browse organic (anthropogenic) specimens identified by the Rock Identifier community.
Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
Petrified Wood
Silicified Wood (SiO2)
Chert (Septarian or Nodular variety)
Microcrystalline Quartz (SiO2)
Chert (Common Opal/Jasper variety)
Microcrystalline Quartz (SiO2) with hydration
Petrified Wood
Silicified wood (Quartz/Chalcedony replacement of organic matter)
Petrified Wood
Silicified wood (Quartz/Chalcedony replacement of organic matter)
Blue Quartzite (Dyed)
Metamorphosed Quartz-rich Sandstone (SiO2 with organic dye)
Pearl
Calcium carbonate (CaCO3) + organic conchiolin (Biogenic Mineral)
Picture Jasper
Silicon Dioxide (SiO2) with iron oxide and organic impurities
Dyed Blue Agate (Dragon Vein Agate)
Silicon Dioxide (SiO2) with artificial cobalt/organic dyes
Crinoid Stem Fossil (Indian Bead)
Crinoid ossicle (Echinodermata)
Shark Tooth Fossil
Otodus obliquus (or similar prehistoric lamniform shark tooth)
Fossilized Insect in Nodular Matrix
Invertebrata / Insecta fossil in sedimentary concretion
Megalodon Shark Tooth
Otodus megalodon
Jasper
Silicon Dioxide (Microcrystalline Quartz, $SiO_2$)
Petrified Wood
Silicified wood (primarily quartz, SiO2)
Petrified Wood
Silicified wood (primarily quartz, SiO2)
Sandstone Pebble (River Rock)
Sandstone (Quartz-rich sedimentary rock with iron oxide staining)
Limestone ( weathered ) / Chert Nodular Rock
Sedimentary rock (primarily Calcium Carbonate, CaCO3, with Microcrystalline Quartz, SiO2)
Banded Chert
Microcrystalline Quartz (SiO2)
Glendonite (Calcite Pseudomorph after Ikaite)
Calcite (CaCO3) pseudomorph after Ikaite (CaCO3·6H2O)
Chert (Flint Nodule)
Microcrystalline and Cryptocrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Sandstone (Red / Iron-stained)
Sandstone (composed predominantly of SiO2 with Fe2O3 cement)
Limestone (Weathered Pebble)
Calcium Carbonate (CaCO3) / Limestone
Chert (Jasper / Petrified Wood)
Microcrystalline Quartz (SiO2)
Jasper (Green Jasper / Chert)
Silicon Dioxide (SiO2 with inclusions)
Petoskey Stone
Hexagonaria percarinata (Calcite / CaCO3)
Fossilized Shark Tooth
Elasmobranchii dentition (calcium phosphate / hydroxyapatite)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Pink Opal
Hydrated Silicon Dioxide (SiO2 · nH2O)
Petrified Wood
Silicified Wood (primarily SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Fossiliferous Rock (likely Dinosaur Fossil in Matrix)
Permineralized Vertebrate Fossil (Calcium Carbonate/Silica replaced bone material)
Petrified Wood
Silicified Wood (primarily SiO2)
Brown Jasper / Chert Pebbles
Microcrystalline Quartz (SiO2) with iron oxide impurities
Chert (specifically Jasper/Flint pebble)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Jasper/Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Petrified Wood
Silicified Wood (primarily SiO2)
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (SiO2)