Brown Agate
Silicon Dioxide (SiO2)
mineral
Category
Mineral Specimen
Browse mineral specimen specimens identified by the Rock Identifier community.
Banded Agate (Gray/White)
Silicon Dioxide (SiO2) - Chalcedony variety
mineral
Rose Quartz
Silicon Dioxide (SiO2)
mineral
Gold Nugget
Native Gold (Au)
mineral
Granite Cobble
Granitoid (typically containing Quartz SiO2, Feldspar KAlSi3O8, and Mica minerals)
igneous
Pyrite
Iron Disulfide (FeS2)
mineral
Red Jasper
Silicon Dioxide (SiO2) with Hematite (Fe2O3) inclusions
mineral
Standing Liberty Quarter (Silver Specimen)
Native Silver alloy (Ag with Cu traces)
mineral
Gray Quartz (Tumbled)
Silicon Dioxide (SiO2)
mineral
Quartz (River Siltstone Quartzite Pebble)
Silicon Dioxide (SiO2)
metamorphic
Pyritic Quartzite
Metequartzite with FeS2 (Pyrite) inclusions
metamorphic
Clear Quartz
Silicon Dioxide (SiO2)
mineral
Sedimentary Breccia
Breccia (Clastic Sedimentary Rock)
sedimentary
Banded Agate
Silicon Dioxide (SiO2) - Chalcedony variety
mineral
Garnet (Almandine or Spessartine likely)
Garnet Group Minerals (e.g., Almandine Fe3Al2(SiO4)3, Pyrope Mg3Al2(SiO4)3, Spessartine Mn3Al2(SiO4)3)
Mineral
Orthoclase Feldspar
Orthoclase (KAlSi3O8)
Mineral
Pyrite
Iron Disulfide (FeS2)
mineral
Chert (with Quartz vein)
Chert (Silicon Dioxide, SiO2)
sedimentary
Quartz Geode/Druzy Quartz
Quartz (SiO₂)
Mineral
Jasper (likely a variety of Yellow or Mustard Jasper)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary (chemically precipitated mineral)
Moqui Marble
Iron Oxide Concretion (Limonite/Hematite shell with Sandstone core)
sedimentary
Basalt with Mineral Vein (Cobble)
Basalt (with likely Quartz/Calcite vein)
Igneous
Chipped Glass/Plastic Fragment
Silicon dioxide (SiO2) for glass (amorphous) or various polymer compounds for plastic
Man-made material (simulant/artifact)
Yellow Apatite Sphere (Polished)
Fluorapatite / Ca5(PO4)3F
mineral
Jasper (Green Jasper/Heliotropic Chert)
Silicon Dioxide (SiO₂)
sedimentary
Limonite-stained Chert/Jasper
Microcrystalline Quartz (SiO2) with Iron Oxides (FeO(OH)·nH2O)
sedimentary
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
sedimentary
Metal Chain Belt with Square Plates
Not applicable (man-made)
Man-made Object (Metalwork)
Ferruginous Quartz
Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions
mineral
Amethyst
Amethyst (Silicon Dioxide containing trace Iron impurities, SiO2)
mineral
Gold Nugget
Native Gold (Au)
mineral
Jasper (specifically Bloodstone or Heliotrope variety)
Silicon Dioxide (SiO2) with iron oxide inclusions
Sedimentary / Mineral
Titanium Aura Quartz
Titanium-coated Silicon Dioxide (SiO2)
mineral (man-enhanced)
Quartz with Mica (likely Muscovite)
Silicon Dioxide (SiO2) with Potassium Aluminum Silicate Hydroxide Fluoride
igneous/metamorphic
Tiger's Eye (Tumbled Blue/Black-Golden variety)
Pseudomorph of Quartz after Crocidolite (SiO2 with Iron inclusions)
metamorphic
Desert Rose (Baryte/Gypsum Rosette)
Baryte (BaSO4) or Gypsum (CaSO4·2H2O)
mineral
Picture Jasper
Silicon Dioxide (SiO2) with iron oxide and clay inclusions
sedimentary
Gold Nugget
Native Gold (Au)
mineral
Metal Alloy (Likely Pewter or Sterling Silver)
Not a natural geological specimen; composed of refined metals. If pewter, it's a tin-based alloy. If sterling silver, it's 92.5% silver and 7.5% other metals (usually copper).
Man-made material (metal)
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Yellow Banded Agate
Silicon Dioxide (SiO₂)
mineral
Gold Ore / Native Gold
Native Gold (Au)
mineral