Ammonite Fossil
Ammonoidea (Calcium carbonate or Pyrite replaced)
sedimentary
Category
Sedimentary (With Some Aspects Of Mineral Replacement)
Browse sedimentary (with some aspects of mineral replacement) specimens identified by the Rock Identifier community.
Galena
Lead(II) sulfide (PbS)
mineral
Banded Gneiss
Gneiss (High-grade regional metamorphic rock)
metamorphic
Sandstone (Quartzose Sandstone)
Arenite (primarily SiO2 with minor Fe2O3)
sedimentary
Petrified Wood
Silicified Wood (primarily SiO2)
sedimentary
Gneiss
Gneiss
metamorphic
Yellow Jasper
Silicon Dioxide (SiO2)
sedimentary
Gneiss
High-grade regional metamorphic rock (Foliated)
metamorphic
Fossiliferous Chert (with Fossil Shells)
Silicon Dioxide (SiO2) with biogenic inclusions
sedimentary
Chert (Yellow Jasper/Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (Jasper)
Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (with Iron Staining)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Magnetite (Iron Ore)
Magnetite (Fe3O4)
mineral
Ferruginous Chert
Silicon dioxide with iron oxide impurities (SiO2 + Fe2O3)
sedimentary
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
metamorphic
Gneiss
Gneiss (High-grade regional metamorphic rock)
Metamorphic
Coral Fossil (Scleractinia)
Scleractinia (Order), primarily CaCO3 (Aragonite or Calcite)
sedimentary
Hematite
Hematite (Fe2O3)
Mineral
N/A - Image is non-geological
Acrylonitrile Butadiene Styrene (ABS) or Polypropylene (PP)
Synthetic material (Plastic/Polymer)
Orthoceras Fossil Limestone
Orthoceras (extinct genus of cephalopod); Limestone matrix (CaCO3)
sedimentary
Gneiss
Metamorphic rock of high-grade regional metamorphism
metamorphic
Jasper
Jasper (Silica/Silicon Dioxide, SiO2)
sedimentary
Gneiss
Gneiss
metamorphic
Chert (varieties include Flint or Jasper)
Chert (cryptocrystalline quartz; SiO₂)
Sedimentary
Chert / Flint
Microcrystalline Quartz (SiO2)
sedimentary
Chert (often colloquially referred to as Flint)
Chert (Cryptocrystalline Quartz, SiO2)
sedimentary
Chert (Nodule)
Chert (primarily Microcrystalline Quartz - SiO2)
sedimentary
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
sedimentary
Concretion
Various mineral compositions, typically carbonate or iron oxide cemented sediment
Sedimentary
Sandstone
Arenite (SiO2, often with CaCO3 or Fe2O3 cement)
sedimentary
Black Limestone with Calcite Veining
Bituminous Limestone (CaCO3 with Organic Carbon inclusions)
sedimentary
River Rock / Stream Pebble
Fluvial Clast / Rounded Sedimentary Particle
Sedimentary Rock (possibly composed of various minerals)
Gneiss (specifically a Granitic Gneiss)
Gneiss (typically composed of Quartz, Feldspar, and Mica/Amphiboles)
metamorphic
Ferruginous Breccia
Breccia with Iron-rich (Hematite/Goethite) Matrix
sedimentary
Mixed Tumbled Stones Collection
Mixed Silicates and Carbonates (Quartz, Amorphous Silica, Carbonates)
multiple
Gneiss
Gneiss (High-grade regional metamorphic rock)
metamorphic
Conglomerate
Conglomerate
Sedimentary
Garnet (likely Almandine, Pyrope, or a blend)
Garnet group minerals: X3Y2(SiO4)3, where X and Y represent various metal ions (e.g., Almandine: Fe3Al2(SiO4)3, Pyrope: Mg3Al2(SiO4)3)
Mineral
Slate
Foliated Metamorphic Rock (composed primarily of Quartz, Muscovite, and Illite)
metamorphic
Ferruginous Chert (Jasper)
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Quartz
Quartz (SiO₂)
Mineral
Gneiss
Gneiss
metamorphic