Pearl (Biogenic Mineral)
Calcium Carbonate (primarily Aragonite) with Conchiolin; CaCO3
Category
Browse organic (geological relative) specimens identified by the Rock Identifier community.
Pearl (Biogenic Mineral)
Calcium Carbonate (primarily Aragonite) with Conchiolin; CaCO3
Chert (Iron-stained)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (specifically Flint or Jasper variant)
Microcrystalline Quartz (SiO2)
Chert (variations include Flint/Jasper)
Cryptocrystalline Silicon Dioxide (SiO2)
Chert (Jasper/Flint variety)
Microcrystalline quartz (SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert (Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Tumbled jasper (likely brecciated or red jasper)
Microcrystalline quartz (chalcedony), SiO₂, with iron-oxide inclusions
Petrified Wood
Silicified Wood (primarily SiO2)
Travertine (often colloquially called Tufa)
Chemical Sedimentary Calcium Carbonate (CaCO3)
Amber (Green variation)
Succinite
Petrified Wood
Silicified wood (Quartz/Chalcedony replacement of Cellulose)
Fossiliferous Sandstone / Mudstone
Sedimentary Rock (Clastic with Fossiliferous Inclusions)
Fossiliferous Limestone
Fossiliferous Limestone (CaCO3 with organic inclusions)
Oak-grain Laminate (Industrial/Decorative Furniture Finish)
Melamine Resin-impregnated Decorative Paper on Particleboard (Cellulose/Thermosetting Plastic)
Petrified Wood
Silicified Wood (SiO2)
Petrified Wood
Silicified Wood (primarily SiO₂ - Silicon Dioxide)
Petrified Wood
Silicified Wood (primarily SiO2)
Petrified Wood
Silicified Wood (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Fossilized Coral
Scleractinia (fossil order), primarily Calcium Carbonate (CaCO3)
Petrified Wood
Silicified Wood (SiO2)
Limestone
Sedimentary rock composed mainly of calcite (CaCO3)
Fossiliferous Limestone / Petrifaction
Sedimentary rock with fossil inclusions / Calcium Carbonate (CaCO3)
Stromatolite
Biogenic Sedimentary Rock (composed predominantly of CaCO3)
Natural White Pearl
Calcium Carbonate (Aragonite/Calcite) with Conchiolin - CaCO3
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony, SiO2)
Vesicular basalt (likely scoriaceous basalt)
Scoriaceous basalt; primarily calcium-rich plagioclase, pyroxene, and olivine with iron-oxide alteration
Petrified Wood
Silicified Wood (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Chert (Yellow or Brown Jasper)
Microcrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (SiO2 - Silicon Dioxide)
Fossilized Coral
Rugosa / Scleractinia (Agatized or Calcitized Coral)
Sandstone with Quartz Crystal Infill
Quartz-cemented quartz arenite
Petrified Wood
Silicified Wood (primarily SiO2 - Silicon Dioxide)
Pearl necklace
Pearl (biogenic calcium carbonate, chiefly aragonite; CaCO₃)
Weathered lateritic ironstone / ferruginous rock
Goethite–hematite-rich laterite, commonly with quartz and clay minerals
Petrified Wood
Silicified Wood (primarily SiO2)
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony, SiO2)
Ironstone Nodules in Chalk/Limestone
Limonite/Goethite concretions (FeO(OH)·nH2O) in Calcium Carbonate matrix (CaCO3)
Petrified Wood
Silicified wood (primarily Silicon Dioxide, SiO2)
Petrified Wood
Silicified Wood (SiO2)