Agate
Silicon Dioxide (Chalcedony), SiO2
sedimentary
Category
Sedimentary Or Metamorphic (Base Substrate)
Browse sedimentary or metamorphic (base substrate) specimens identified by the Rock Identifier community.
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Agate
Silicon Dioxide (Chalcedony), SiO2
sedimentary
Agate
Silicon dioxide (Chalcedony), SiO2
sedimentary
Agate
Silicon Dioxide (SiO2)
sedimentary
Agate
Silicon Dioxide (Chalcedony), SiO2
sedimentary
Agate
Silicon Dioxide (Chalcedony), SiO2
sedimentary
Agate
Silicon Dioxide (Chalcedony), SiO2
sedimentary
Agate
Chalcedony (SiO2)
sedimentary
Gneiss
Metamorphic Gneiss (High-grade regional metamorphism)
metamorphic
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
sedimentary
Sandstone (with Iron Staining)
Clastic Sedimentary Rock (primarily SiO2 with Fe2O3 oxides)
sedimentary
Quartz / Quartzite Fragment
Silicon Dioxide (SiO2)
igneous, sedimentary, or metamorphic (mineral-based)
Gneiss (Granulite / Foliated Metamorphic Rock)
Gneiss
metamorphic
Native Gold (in earring form)
Gold (Au)
mineral
Ironstone Concretion / Limonite Node
Ferruginous Sedimentary Rock (composed primarily of Limonite FeO(OH)·nH2O and Goethite)
sedimentary
Weathered quartz-rich rock, possibly sandstone or quartzite
Indeterminate; likely quartz sandstone (SiO₂-rich), possibly weakly metamorphosed quartzite
sedimentary
Greenstone
Metabasalt
metamorphic
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
sedimentary
Gneiss
Gneiss
metamorphic
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Quartzite Pebble
Metamorphic Quartzite (SiO2)
metamorphic
Ferruginous Sandstone
Arenite with Iron-oxide cement (composed of Quartz and Limonite/Hematite)
sedimentary
Gneiss (Banded Gneiss Cobble)
Gneiss
metamorphic
Gneiss
Gneiss (High-grade metamorphic rock)
metamorphic
Gneiss
Gneiss (High-grade metamorphic rock)
metamorphic
Gneiss
Metamorphic Gneiss (High-grade regional metamorphism)
metamorphic
Basalt with Caliche Crust
Aphanitic Mafic Igneous Rock with Calcium Carbonate (CaCO3) coating
igneous
Phyllite
Phyllite (Foliated metamorphic rock)
metamorphic
Garnet Schist
Garnet-bearing Mica Schist (variety of compositions, often Al2SiO5 with X3Y2(SiO4)3)
metamorphic
Prehnite with Epidote
Prehnite (Ca2Al(AlSi3O10)(OH)2) with Epidote (Ca2(Al2,Fe)(SiO4)(Si2O7)O(OH))
mineral
Pyritic Gneiss (with Garnet)
Gneiss containing Pyrite (FeS2) and Almandine Garnet (Fe3Al2(SiO4)3)
metamorphic
Quartz-rich river pebble, likely milky quartz
Milky quartz (SiO₂), possibly a quartzite or quartz-rich silicate pebble
mineral
Calcite
Calcium Carbonate (CaCO3)
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Chert (varieties include Flint and Jasper)
Microcrystalline or Cryptocrystalline Silicon Dioxide (SiO2)
sedimentary
Chert (Nodular Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (and Flint)
Silicon Dioxide (SiO2)
sedimentary
Coquina
Coquina (Bioclastic Limestone)
sedimentary
Chert (and Chert-Jasper mix)
Microcrystalline Quartz (SiO2)
sedimentary
Coquina
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Chert (Pebble)
Silicon Dioxide (SiO2)
sedimentary