Rock Identifier

Category

Mineral (Biogenic Replacement)

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

Jasper (Brown Iron-Rich Variety) (Silicon Dioxide (SiO2) with Fe2O3 (Iron Oxide/Crystalline Quartz)) — sedimentary

Jasper (Brown Iron-Rich Variety)

Silicon Dioxide (SiO2) with Fe2O3 (Iron Oxide/Crystalline Quartz)

Banded Jasper (Silicon Dioxide (SiO2) with iron oxide inclusions) — sedimentary

Banded Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

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

Tiger's Eye

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

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

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2 with iron inclusions)

Chert (Jasper/Limonitic Chert) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Jasper/Limonitic Chert)

Microcrystalline Quartz (SiO2)

Fossiliferous Chert with Brachiopod Impression (Chert (SiO2) containing Brachiopoda fossil remains) — sedimentary

Fossiliferous Chert with Brachiopod Impression

Chert (SiO2) containing Brachiopoda fossil remains

Celestine (Celestite) (Strontium Sulfate (SrSO4)) — mineral

Celestine (Celestite)

Strontium Sulfate (SrSO4)

Specular Hematite and Magnetite Ore (Iron Oxide (Fe2O3 and Fe3O4)) — mineral

Specular Hematite and Magnetite Ore

Iron Oxide (Fe2O3 and Fe3O4)

Hematite (Iron Ore) (Hematite (Fe2O3)) — mineral

Hematite (Iron Ore)

Hematite (Fe2O3)

Yellow Jade (often Serpentine or Dolomite) (Primarily Serpentine (Mg3Si2O5(OH)4) or Dolomite (CaMg(CO3)2), though the term 'yellow jade' is also sometimes applied to varieties of true nephrite or jadeite.) — Mineral, often a rock given its aggregate nature

Yellow Jade (often Serpentine or Dolomite)

Primarily Serpentine (Mg3Si2O5(OH)4) or Dolomite (CaMg(CO3)2), though the term 'yellow jade' is also sometimes applied to varieties of true nephrite or jadeite.

Mineral, often a rock given its aggregate nature

Chert (often called Flint when dark or found in chalk) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (often called Flint when dark or found in chalk)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

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

Galena

Lead(II) sulfide (PbS)

Yellow Chert or Jasper (Silicon Dioxide (SiO2)) — sedimentary

Yellow Chert or Jasper

Silicon Dioxide (SiO2)

Sphalerite in Matrix (Polished Point) (Zinc sulfide (Zn,Fe)S) — mineral

Sphalerite in Matrix (Polished Point)

Zinc sulfide (Zn,Fe)S

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Synthetic Sapphire and Ion-X Glass (Single-crystal Alumina (Al2O3) and Ion-strengthened Aluminosilicate Glass) — mineral

Synthetic Sapphire and Ion-X Glass

Single-crystal Alumina (Al2O3) and Ion-strengthened Aluminosilicate Glass

Popcorn (Zea mays everta (P. Wilson) (Botanical name for the corn variety)) — Organic/Biogenic

Popcorn

Zea mays everta (P. Wilson) (Botanical name for the corn variety)

Organic/Biogenic

Chert (specifically Flint or Jasper variant) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (specifically Flint or Jasper variant)

Microcrystalline Quartz (SiO2)

Chert (Commonly known as Flint) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Commonly known as Flint)

Microcrystalline Quartz (SiO2)

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

Chert (Tripolitic Chert / Flint Nodules)

Microcrystalline Quartz (SiO2)

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

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

Galena

Lead(II) sulfide (PbS)

Calcite (Calcite (CaCO₃)) — Mineral

Calcite

Calcite (CaCO₃)

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

Chert (Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

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

Galena

Lead(II) sulfide (PbS)

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)

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)

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

Chert (Jasper/Chalcedony variety)

Silicon Dioxide (SiO2)

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

Petrified Wood

Silicified Wood (primarily SiO2 - Silicon Dioxide)

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

Rhodonite

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

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

Chert (Jasper variation)

Microcrystalline Quartz (SiO2)

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

Black Jasper

Black Jasper (Silicate mineral - SiO2)

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

Chert / Flint

Microcrystalline Quartz (SiO2)

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

Megalodon Shark Tooth Fossil

Otodus megalodon (fossilized in sedimentary matrix)

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)