Sandstone (Fluvial Pebble)
Arenite
sedimentary
Category
Sedimentary (Microcrystalline Silicate)
Browse sedimentary (microcrystalline silicate) specimens identified by the Rock Identifier community.
Learn about Sedimentary (Microcrystalline Silicate) in the encyclopedia
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Claystone / Mudstone
Mudstone (Hydrous aluminum silicate rich rock)
sedimentary
Light-colored weathered stone, possibly limestone or quartz-rich rock
Indeterminate; likely calcitic limestone (mostly CaCO₃) or quartz sandstone (SiO₂)
sedimentary
Quartz Vein in Host Rock
Silicon dioxide (SiO2) veining in silicate matrix
sedimentary
Sea Glass
Man-made silicate glass weathering product
sedimentary
Bentonite Clay
Al2O3·4SiO2·H2O (Hydrous aluminum silicate)
sedimentary
Siltstone
Siltstone (composed of mixed silicate minerals and clay)
sedimentary
Likely limestone or calcareous fossil fragment
Calcite-rich carbonate rock; possibly bioclastic limestone (CaCO₃)
sedimentary
Picasso Stone
Metamorphosed Calcium Carbonate (Limestone)
sedimentary
Greenstone / Glauconitic Siltstone
Metabasalt or Glauconite-rich Sedimentary Rock
metamorphic or sedimentary
Sandstone (Ferruginous)
Arenite (with Iron Oxide)
sedimentary
Tree Agate
Dendritic Agate (Silicon Dioxide, SiO2)
mineral
Petoskey Stone (Petrified Favosites)
Favosites (extinct colonial coral), CaCO3 with Silica replacement
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Almandine Garnet
Iron aluminum silicate - Fe3Al2(SiO4)3
metamorphic
Sandstone (Ferruginous)
Arenite (primarily SiO2 with Fe2O3 inclusions)
sedimentary
Sandstone (Ferruginous)
Arenite (complex silicate composition with iron oxides)
sedimentary
Common Opal (Potch)
Hydrated Silica (SiO2·nH2O)
mineral
Chert / Quartz Pebble
Silicon Dioxide (SiO2)
sedimentary
Ruby Zoisite
Anyolite (Calcium aluminium silicate with Chromium/Corundum inclusions)
metamorphic
Mica Schist with Garnet inclusions
Mica Schist (primarily Muscovite and Biotite - KAl2(AlSi3O10)(OH)2)
metamorphic
Pyritic Gneiss (with Garnet)
Gneiss containing Pyrite (FeS2) and Almandine Garnet (Fe3Al2(SiO4)3)
metamorphic
Aquamarine (Pendant) and Jasper (Beads)
Beryllium aluminum silicate (Be3Al2Si6O18) with Chalcedony (SiO2)
mineral
Mixed Mineral Assortment (Pyrite, Kyanite, Agate, Jasper)
FeS2 (Pyrite), Al2SiO5 (Kyanite), SiO2 (Agate/Jasper)
mineral
Greenstone / Serpentinite Pebble
Serpentinite (Hydrated Magnesium Silicate, Mg3Si2O5(OH)4)
metamorphic
Banded Gneiss
Gneiss (high-grade metamorphic silicate rock)
metamorphic
Quartz–feldspar–mica metamorphic rock, likely gneiss
Gneiss; composition commonly quartz (SiO₂), feldspars, biotite/hornblende, and minor accessory minerals
metamorphic
Conglomerate
Conglomerate (SiO2 matrix with various silicate clasts)
sedimentary
Blue Quartz (Aventurine)
Silicon Dioxide (SiO2) with Crocidolite or Magnesio-riebeckite inclusions
metamorphic
Anthracite Coal
Anthracite (Carbon-rich metamorphic rock)
metamorphic
Marble
Recrystallized Carbonate Rock (CaCO3)
metamorphic
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
mineral
Siltstone
Siltstone (primarily SiO2 with various silicates)
sedimentary
Ironstone Pebble
Iron-rich Sedimentary Rock (Fe2O3 / FeO(OH))
sedimentary
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
mineral
Banded Calcite (often sold as 'Mexican Onyx' or 'Calcite Onyx')
Calcite (Calcium Carbonate, CaCO3)
sedimentary
Green Banded Chert (Agate/Jasper)
Silicon Dioxide (SiO2) with trace impurities of Chlorite or Glauconite
sedimentary
Sandstone (Ferruginous)
Arenite with Iron-Oxide Cement
sedimentary
Luminous Stone (Glow-in-the-dark Synthetic/Man-made Stone)
Strontium Aluminate tinted glass or resin (Crystalline silicate/oxide mix)
mineral (synthetic)
Banded Chert / Cryptocrystalline Quartz
Silicon Dioxide (SiO2)
sedimentary
Riverstone (Quartzite/Granite Cobble)
Silicon Dioxide (SiO2) based Quartzite or Silicate-rich Granite
metamorphic or igneous
Bloodstone (Heliotrope)
Silicon Dioxide (SiO2) with iron silicate and iron oxide inclusions
Mineral