Banded Calcite (often sold as 'Mexican Onyx')
Calcite (Calcium Carbonate, CaCO3)
Mineral / Sedimentary Rock
Category
Mineral Specimen
Browse mineral specimen specimens identified by the Rock Identifier community.
Fossilized Bone Fragment
Permineralized Vertebrate Bone (Hydrox yapatite replaced by Silica or Calcite)
sedimentary
Ruby (Corundum)
Aluminum Oxide (Al2O3) with Chromium traces
mineral
Orange Calcite (likely polished specimen)
Calcite
Mineral
Pyrite
Iron Disulfide (FeS2)
mineral
Rock Crystal Quartz
Quartz (SiO₂)
Mineral
Schist (specifically Mica Schist)
Mica Schist (primarily composed of Muscovite KAl2(AlSi3O10)(OH)2 and Biotite)
metamorphic
Lapis Lazuli
Lazurite-rich metamorphic rock (approx. Na6Ca2(Al6Si6O24)(S,SO4,Cl)1,2)
metamorphic
Quartz Pebble (Iron-stained)
Silicon Dioxide (SiO2)
mineral
Banded Sandstone
Arenite (composed primarily of Quartz: SiO2)
sedimentary
Sandstone with Ironstone Banding
Clastic Sandstone (composed of Quartz with Hematite/Limonite bonding)
sedimentary
Sandstone (likely Quartzose Sandstone)
Arenite (primarily SiO2)
sedimentary
Sandstone (with Iron Staining)
Arenite (composed primarily of SiO2 with Fe2O3 staining)
sedimentary
Quartz (pebble)
Quartz (SiO₂)
Mineral
Sandstone (Muddy/Silty Variety)
Arenite with high silt/clay content (clastic sedimentary rock)
sedimentary
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Milky Quartz with Iron Staining
Quartz (Silicon Dioxide - SiO2)
Mineral
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
mineral
Rose Quartz
Silicon Dioxide (SiO2)
mineral
Pyrite
Iron Disulfide (FeS2)
mineral
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of Titanium, Iron, or Manganese
mineral
Celestite (Celestine)
Celestine (Strontium Sulfate, SrSO4)
Mineral
Amethyst
Silicon Dioxide with Iron impurities (SiO2)
mineral
Sandstone with Foliose Lichen
Arenite (Rock matrix) with Xanthoparmelia or Flavoparmelia (Lichen genus)
sedimentary
Quartz (Fieldstone/Pebble)
Silicon Dioxide (SiO2)
mineral
Yellow Chalcedony (Carnelian/Yellow Agate)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Mineral
Optical Calcite (Iceland Spar)
Calcite (Calcium Carbonate, CaCO3)
mineral
Granite Pegmatite
Coarse-grained Granite (SiO2 - Aluminum and Alkalies)
igneous
Banded Agate (specifically Botswana Agate appearance)
Silicon Dioxide (SiO2) - variety of Chalcedony
mineral
White Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
mineral
Almandine Garnet
Iron aluminum silicate (Fe3Al2(SiO4)3)
Mineral
Milk Quartz (White) and Yellow Aventurine (Yellow)
Silicon Dioxide (SiO2)
mineral
Tanzanite (Blue Zoisite)
Ca2Al3(SiO4)(Si2O7)O(OH) + (V) - Vanadium-bearing Zoisite
mineral
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
mineral
Ruby in Kyanite
Corundum in Disthene (Al2SiO5 + Al2O3)
metamorphic
Fossilized Shark Tooth (Cretaceous to Neogene)
Elasmobranchii dental fossil (likely Squalicorax or similar species)
mineral (biogenic replacement)
Ferruginous Quartz (Iron-stained Quartz)
Silicon Dioxide with Iron Oxide (SiO2 with traces of Fe2O3/FeO(OH))
mineral
Gneiss
Gneiss
metamorphic
Rough Diamond
Diamond (Native Carbon, C)
mineral
Veined Quartz
SiO2 (Silicon Dioxide)
Mineral
Rose Quartz with Hematite inclusions
Silicon Dioxide (SiO2) with Fe2O3 inclusions
mineral