Agate
Silicon dioxide (SiO2)
mineral
Category
Mineralological Specimen
Browse mineralological specimen specimens identified by the Rock Identifier community.
Learn about Mineralological Specimen in the encyclopedia
View all →
Galena with Pyrite on Matrix
Lead(II) sulfide (PbS) with Iron disulfide (FeS2)
mineral
Yellow Agate (Chalcedony)
Silicon Dioxide (SiO2)
mineral
Clear Quartz
Silicon Dioxide (SiO2)
mineral
Emerald in Matrix
Beryl (Be3Al2Si6O18)
mineral
Quartz
Silicon Dioxide (SiO2)
mineral
Tumbled Agate
Silicon Dioxide (Chalcedony / Quartz)
gemstone
Small polished dark mineral or gemstone fragment
Indeterminate; possibly smoky quartz, obsidian, or dark tourmaline
mineral
Granite Cobble
Phaneritic Felsic Igneous Rock
igneous
Obsidian
Volcanic Glass (Amorphous Silicon Dioxide)
igneous
Vesicular Basalt (Iron Scoria)
Aphanitic Mafic Igneous Rock with Vesicular Texture
igneous
Dumortierite Quartz
Dumortierite-bearing Quartz (SiO2 with Al7BO3(SiO4)3O3)
mineral
Rose Quartz in Matrix
Silicon Dioxide (SiO2) with traces of Titanium, Iron, or Manganese
mineral
Sandstone (Ferruginous)
Sandstone (clastic sedimentary rock, mainly SiO2 with iron oxide cement)
sedimentary
Pyrite
Iron Pyrite (FeS2)
mineral
Quartz with Iron Staining
Silicon Dioxide (SiO2)
mineral
Citrine Quartz
Silicon Dioxide (SiO2)
mineral
Chalcedony (Agate/Common Opal blend)
Microcrystalline Quartz (SiO2)
mineral
Granite (Orthoclase rich)
Granite (composed primarily of Quartz and Potassium Feldspar KAlSi3O8)
igneous
Diamond (faceted)
Carbon (C)
gemstone
Diamond (Cut and Faceted)
Carbon (C)
gemstone
Diamond
Carbon (C)
gemstone
Diamond
Carbon (C)
mineral
N/A - Non-Geological Item
not a rock/mineral
Agate
Agate (Chalcedony), SiO2
Mineral
Peridot (Olivine)
Magnesium Iron Silicate (Mg, Fe)2SiO4
mineral
Unidentified Dark Mineral or Rock
Indeterminate (Likely Silicon Dioxide or Carbon-based)
mineral
Quartz Geode
Silicon Dioxide (SiO2)
mineral
Pyrite in Matrix
Iron Sulfide (FeS2)
mineral
Yellow Quartz Pebble
Quartz (Silicon Dioxide - SiO2)
mineral
Iron-stained Quartz
Silicon Dioxide with Limonite (SiO2 + FeO(OH)·nH2O)
mineral
Banded Calcite (Honey Calcite)
Calcium Carbonate (CaCO3)
mineral
Pegmatite with Schorl (Black Tourmaline) and Mica
Pegmatite (complex association of NaAlSi3O8, NaFe3Al6(BO3)3Si6O18(OH)4, and KAl2(AlSi3O10)(OH,F)2)
igneous
Iron-rich quartzite or weathered ironstone
Quartzite dominated by quartz (SiO₂), with iron oxides/hydroxides such as hematite and goethite
metamorphic
Vein-filled Sedimentary Rock
Silicified sedimentary rock with quartz/calcite vein
sedimentary
Fossiliferous Mudstone / River Pebble
Sedimentary rock with trace fossil or inclusion
sedimentary
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Garnet in Matrix (Schist or Quartz)
Almandine Garnet, Fe3Al2(SiO4)3
metamorphic
Greenschist
Greenschist (Chlorite-Epidote-Actinolite Schist)
metamorphic
Chert / Jasper
Silicon Dioxide (SiO2)
sedimentary
Shark Tooth Fossil
Carcharodonta (order Lamniformes), likely Carcharias spp.
fossil
Quartz
Silicon dioxide (SiO2)
mineral