Rock Identifier

Category

Mineral (Biogenic Replacement)

Browse mineral (biogenic replacement) specimens identified by the Rock Identifier community.

Sodalite (Na8(Al6Si6O24)Cl2 (Sodium Aluminum Silicate Chloride)) — mineral

Sodalite

Na8(Al6Si6O24)Cl2 (Sodium Aluminum Silicate Chloride)

Chalcedony (Botryoidal or Tumbled) (Chalcedony (SiO₂)) — mineral

Chalcedony (Botryoidal or Tumbled)

Chalcedony (SiO₂)

Ocean Jasper (Orbicular Jasper) (Spherulitic Chalcedony (SiO2)) — sedimentary

Ocean Jasper (Orbicular Jasper)

Spherulitic Chalcedony (SiO2)

Chert (Chalcedony/Agate Pebble) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Chalcedony/Agate Pebble)

Microcrystalline Quartz (SiO2)

Chalcedony (likely iron-stained agate) (Microcrystalline quartz, SiO₂ (chalcedony/agate)) — mineral

Chalcedony (likely iron-stained agate)

Microcrystalline quartz, SiO₂ (chalcedony/agate)

Chert Nodule (Microcrystalline Quartz (SiO2)) — sedimentary

Chert Nodule

Microcrystalline Quartz (SiO2)

Fossilized Shark Tooth (Elasmobranchii gen. indet.) — fossil

Fossilized Shark Tooth

Elasmobranchii gen. indet.

Chert (River Pebble) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (River Pebble)

Microcrystalline Quartz (SiO2)

Petrified Wood (Silicified Wood (primarily SiO2 - Silicon Dioxide)) — mineral

Petrified Wood

Silicified Wood (primarily SiO2 - Silicon Dioxide)

Chert (Jasper/Chalcedony variety) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Jasper/Chalcedony variety)

Silicon Dioxide (SiO2)

Fossil Rugose Coral (Horn Coral) (Order Rugosa (likely Grewingkia or Heliophyllum species); Calcium Carbonate (CaCO3)) — sedimentary

Fossil Rugose Coral (Horn Coral)

Order Rugosa (likely Grewingkia or Heliophyllum species); Calcium Carbonate (CaCO3)

Chert (Flint) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Flint)

Microcrystalline Quartz (SiO2)

Chert (variant Flint) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (variant Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Galena (Lead(II) sulfide (PbS)) — mineral

Galena

Lead(II) sulfide (PbS)

Chert / Flint Pebble (Microcrystalline Silica (SiO2)) — sedimentary

Chert / Flint Pebble

Microcrystalline Silica (SiO2)

Likely galena-bearing ore (Galena (PbS), possibly mixed with quartz or carbonate gangue) — mineral

Likely galena-bearing ore

Galena (PbS), possibly mixed with quartz or carbonate gangue

Grey Chalcedony (Tumbled) (Chalcedony (SiO2)) — mineral

Grey Chalcedony (Tumbled)

Chalcedony (SiO2)

Tiger's Eye (Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxide inclusions)) — mineral

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxide inclusions)

Red Tiger's Eye (SiO2 (Silicon Dioxide) - Pseudomorph of Quartz after Crocidolite) — mineral

Red Tiger's Eye

SiO2 (Silicon Dioxide) - Pseudomorph of Quartz after Crocidolite

Chert (Jasper variation) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Jasper variation)

Microcrystalline Quartz (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Black Jasper (Black Jasper (Silicate mineral - SiO2)) — sedimentary

Black Jasper

Black Jasper (Silicate mineral - SiO2)

Megalodon Shark Tooth Fossil (Otodus megalodon (fossilized in sedimentary matrix)) — sedimentary

Megalodon Shark Tooth Fossil

Otodus megalodon (fossilized in sedimentary matrix)

Pyrite (Fool's Gold) (Iron Sulfide (FeS2)) — mineral

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Chert (Tripolitic Chert / Flint Nodules) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Tripolitic Chert / Flint Nodules)

Microcrystalline Quartz (SiO2)

Fossilized Sea Urchin (Echinoid) (Echinoidea (Class); commonly Clypeasteroida for sand dollar types) — sedimentary (fossil)

Fossilized Sea Urchin (Echinoid)

Echinoidea (Class); commonly Clypeasteroida for sand dollar types

sedimentary (fossil)

Chert / Flint (Microcrystalline Quartz (SiO2)) — sedimentary

Chert / Flint

Microcrystalline Quartz (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Chert (Jasper/Flint variety) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Jasper/Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Flint Nodules) (Chert (Silicon Dioxide, SiO2)) — sedimentary

Chert (Flint Nodules)

Chert (Silicon Dioxide, SiO2)

Flint (Chert (a form of cryptocrystalline quartz, chemical formula SiO₂)) — Mineral

Flint

Chert (a form of cryptocrystalline quartz, chemical formula SiO₂)

Chert (Flint) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Orthoceratid Fossil in Limestone (Orthoceras (extinct genus of Nautiloid Cephalopod)) — sedimentary

Orthoceratid Fossil in Limestone

Orthoceras (extinct genus of Nautiloid Cephalopod)

Petrified Wood (Silicified Wood (SiO2)) — fossil

Petrified Wood

Silicified Wood (SiO2)

Muscovite Schist (KAl2(AlSi3O10)(OH)2 (Muscovite) in Schist Matrix) — metamorphic

Muscovite Schist

KAl2(AlSi3O10)(OH)2 (Muscovite) in Schist Matrix

Rhodonite (Rhodonite (Manganese Silicate), (Mn,Fe,Mg,Ca)SiO3) — mineral

Rhodonite

Rhodonite (Manganese Silicate), (Mn,Fe,Mg,Ca)SiO3

Ammonite Fossil in Matrix (Ammonoidea subclass (e.g., Arietites or similar genera)) — fossil

Ammonite Fossil in Matrix

Ammonoidea subclass (e.g., Arietites or similar genera)

Black Chert (Flint) (Silicon Dioxide (SiO2)) — sedimentary

Black Chert (Flint)

Silicon Dioxide (SiO2)

Sea Urchin Fossil (Echinoidea (test/fossil)) — fossil

Sea Urchin Fossil

Echinoidea (test/fossil)

Chert (Lithic flake / Arrowhead fragment) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Lithic flake / Arrowhead fragment)

Microcrystalline Quartz (SiO2)

Black Jasper (Silicon Dioxide (SiO2) with impurities) — sedimentary

Black Jasper

Silicon Dioxide (SiO2) with impurities

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)