Rock Identifier

Category

Mineral (Biogenic Replacement)

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

Petrified Wood (Silicon Dioxide (SiO2) permineralized organic matter) — sedimentary

Petrified Wood

Silicon Dioxide (SiO2) permineralized organic matter

Tiger's Eye (Tiger's Eye (a variety of Chalcedony, which is a microcrystalline quartz with fibrous inclusions of oxidized crocidolite)) — Mineral

Tiger's Eye

Tiger's Eye (a variety of Chalcedony, which is a microcrystalline quartz with fibrous inclusions of oxidized crocidolite)

Flint Nodule (Microcrystalline Quartz (SiO2)) — sedimentary

Flint Nodule

Microcrystalline Quartz (SiO2)

Petrified Wood (Silicified wood, primarily composed of Quartz (SiO2)) — Mineral, often found in sedimentary deposits

Petrified Wood

Silicified wood, primarily composed of Quartz (SiO2)

Mineral, often found in sedimentary deposits

Calcite (Calcite (CaCO3)) — Mineral

Calcite

Calcite (CaCO3)

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

Chert / Flint

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Red Jasper (Red Jasper (variety of Chalcedony, SiO₂)) — Mineral

Red Jasper

Red Jasper (variety of Chalcedony, SiO₂)

Limonite-pseudomorph after Pyrite (Prophecy Stone) (Goethite and Limonite secondary minerals (FeO(OH)·nH2O) replacing Pyrite (FeS2)) — mineral

Limonite-pseudomorph after Pyrite (Prophecy Stone)

Goethite and Limonite secondary minerals (FeO(OH)·nH2O) replacing Pyrite (FeS2)

Petrified Wood (Silicified Wood) (Silicified Wood / Silicon Dioxide (SiO2)) — metamorphic

Petrified Wood (Silicified Wood)

Silicified Wood / Silicon Dioxide (SiO2)

Tiger's Eye (Pseudomorph of Quartz after Crocidolite (SiO2)) — metamorphic

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2)

Larimar (Blue Pectolite (NaCa2Si3O8(OH))) — mineral

Larimar

Blue Pectolite (NaCa2Si3O8(OH))

Petrified Wood (Silicified Wood (SiO2 - Quartz/Chalcendony replacing organic matter)) — sedimentary

Petrified Wood

Silicified Wood (SiO2 - Quartz/Chalcendony replacing organic matter)

Petrified Wood (Agatized/Silicified Wood) (Silicified Wood (SiO2 - Silicon Dioxide)) — metamorphic

Petrified Wood (Agatized/Silicified Wood)

Silicified Wood (SiO2 - Silicon Dioxide)

Chert (with Limonite staining) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (with Limonite staining)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (with Iron Staining) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (with Iron Staining)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Fossilized Coral (Petoskey Stone type) (Hexagonaria percarinata (Fossilized Rugose Coral)) — sedimentary

Fossilized Coral (Petoskey Stone type)

Hexagonaria percarinata (Fossilized Rugose Coral)

Petrified Wood (Silicified Wood (SiO2 - Silicon Dioxide)) — sedimentary

Petrified Wood

Silicified Wood (SiO2 - Silicon Dioxide)

Pyrite (Pyrite (Iron sulfide, FeS₂)) — Mineral

Pyrite

Pyrite (Iron sulfide, FeS₂)

Red Jasper (Jasper (Silicon Dioxide with iron oxide inclusions), SiO2) — mineral

Red Jasper

Jasper (Silicon Dioxide with iron oxide inclusions), SiO2

Olivine in Basalt (Peridot) (Magnesium Iron Silicate (Mg, Fe)2SiO4 in Vesicular Basalt) — igneous

Olivine in Basalt (Peridot)

Magnesium Iron Silicate (Mg, Fe)2SiO4 in Vesicular Basalt

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

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Echinoid Fossil (Sea Urchin) (Echinoidea (specifically likely Schizaster or similar genus), calcium carbonate (CaCO3)) — sedimentary

Echinoid Fossil (Sea Urchin)

Echinoidea (specifically likely Schizaster or similar genus), calcium carbonate (CaCO3)

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

Chert (Jasper variety)

Silicon Dioxide (SiO2)

Chert (Jasper variety) with Iron Oxide staining (Cryptocrystalline Quartz (SiO2) with Goethite/Limonite impurities) — sedimentary

Chert (Jasper variety) with Iron Oxide staining

Cryptocrystalline Quartz (SiO2) with Goethite/Limonite impurities

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

Chert (Flint variety)

Silicon Dioxide (SiO2)

Chert (variations include Chalcedony and Flint) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (variations include Chalcedony and Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (containing Flint and Chalcedony) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (containing Flint and Chalcedony)

Microcrystalline Quartz (SiO2)

Chert (specifically a stream-worn Chert Nodule) (Sedimentary Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (specifically a stream-worn Chert Nodule)

Sedimentary Cryptocrystalline Quartz (SiO2)

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

Petrified Wood

Silicified Wood (primarily SiO2 - Silicon Dioxide)

Dinosaur Bone (Gembone) (Petrified Dinosaur Bone (Apatite/Silica replacement)) — sedimentary

Dinosaur Bone (Gembone)

Petrified Dinosaur Bone (Apatite/Silica replacement)

Red Jasper (Silicon dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions) — sedimentary

Red Jasper

Silicon dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions

Mookaite Jasper (Silicified Radiolarite (SiO2)) — sedimentary

Mookaite Jasper

Silicified Radiolarite (SiO2)

Petrified Wood (Silicified Wood (SiO2 - primarily Quartz/Chalcedony/Opal)) — Mineral/Fossil (Sedimentary context)

Petrified Wood

Silicified Wood (SiO2 - primarily Quartz/Chalcedony/Opal)

Mineral/Fossil (Sedimentary context)

Galena (Galena (Lead Sulfide), PbS) — mineral

Galena

Galena (Lead Sulfide), PbS

Petrified Wood (Silicified Wood (SiO2 - Quartz/Chalcedony replacement)) — Mineral / Fossil

Petrified Wood

Silicified Wood (SiO2 - Quartz/Chalcedony replacement)

Mineral / Fossil

Amber Inlay Jewelry (Fossilized Resin (C10H16O)) — Organic Gemstone (Biogenic)

Amber Inlay Jewelry

Fossilized Resin (C10H16O)

Organic Gemstone (Biogenic)

Petrified Wood (Silicified wood (primarily Silicon Dioxide - SiO2)) — mineral (silicate-replaced organic material)

Petrified Wood

Silicified wood (primarily Silicon Dioxide - SiO2)

mineral (silicate-replaced organic material)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

White Jade (Nephrite) (Nephrite, Ca2(Mg,Fe)5Si8O22(OH)2) — Mineral

White Jade (Nephrite)

Nephrite, Ca2(Mg,Fe)5Si8O22(OH)2

Petrified Wood (Silicified wood (Quartz/Chalcedony replacement of organic matter)) — sedimentary

Petrified Wood

Silicified wood (Quartz/Chalcedony replacement of organic matter)

Synthetic Ruby (Jewel Bearings) (Synthetic Corundum (Al2O3 doped with Chromium)) — mineral

Synthetic Ruby (Jewel Bearings)

Synthetic Corundum (Al2O3 doped with Chromium)

Yellow Chalcedony (Chalcedony (a cryptocrystalline variety of Quartz, SiO₂)) — Mineral

Yellow Chalcedony

Chalcedony (a cryptocrystalline variety of Quartz, SiO₂)