Amethyst
Silicon dioxide (SiO2) with iron impurities
mineral
Category
Mineral And Organic Gemstone
Browse mineral and organic gemstone specimens identified by the Rock Identifier community.
Sunstone
Plagioclase Feldspar ((Ca,Na)(Al,Si)4O8)
mineral
Chert (with Limestone/Dolomite host)
Microcrystalline Quartz (SiO2)
sedimentary
Moqui Marble (Shaman Stone)
Iron Oxide Concretion (composed primarily of Quartz sand with Hematite/Goethite shell)
sedimentary
Dinosaur Bone (Gembone)
Agatized Dinosaur Bone (Silicified Paleo-osteoid)
metamorphic
Fossilized Coral
Scleractinian Anthozoa (Fossilized Calcium Carbonate, CaCO3)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
metamorphic
Shale with Iron Oxide Staining
Fissile Mudstone (primarily clay minerals and quartz)
sedimentary
Yellow Chert (Jasper)
Silicon Dioxide (SiO2)
sedimentary
Graphite
Graphite (Native Carbon), Formula: C
Metamorphic
Glauconitic Sandstone (Greensand)
Glauconitic Sandstone ((K, Na)(Fe3+, Al, Mg)2(Si, Al)4O10(OH)2)
sedimentary
Chrysocolla in Cuprite (Sonoran Sunrise)
Cu2-xAlx(H2-xSi2O5)(OH)4·n(H2O) (Chrysocolla) and Cu2O (Cuprite)
mineral
Shale with Pyrite
Clastic sedimentary rock containing Iron Disulfide (FeS2)
sedimentary
Chert (containing Calcite or Quartz inclusions)
Silicon Dioxide (SiO2) with varying mineral impurities
sedimentary
Aragonite (Star Cluster or Twinned variety)
Aragonite (Calcium Carbonate, CaCO3)
mineral
Unknown Organic Object (likely a berry or fruit)
Not applicable; this is not a geological specimen. If it were a cranberry, its scientific name would be Vaccinium macrocarpon; if a cherry, it would be Prunus avium or Prunus cerasus.
Organic Material (likely a fruit or berry)
Petrified Wood
Silicified Wood (primarily Chalcedony/Quartz, SiO2)
sedimentary
Ammonite Fossil
Ammonoidea (Calcium carbonate - CaCO3)
sedimentary
Tufa
Calcareous Tufa (Calcium Carbonate, CaCO3)
sedimentary
Petrified Wood
Silicified Wood (primarily SiO2)
sedimentary
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony, formula: SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
metamorphic
Chert (with Quartz vein/coating)
Microcrystalline Quartz (SiO2)
sedimentary
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
mineral
Rhodochrosite
Manganese carbonate (MnCO3)
mineral
Aquamarine
Beryl (Be3Al2Si6O18)
mineral
Quartz in Matrix (possibly Basalt or Siltstone host)
Silicon Dioxide (SiO2) in Host Rock
mineral
Celestine (Celestite)
Strontium sulfate (SrSO4)
mineral
Diamond
Diamond (pure Carbon, C)
mineral
Halite (Himalayan Pink Salt)
Halite - NaCl (Sodium Chloride)
Mineral (Evaporite)
Lemon (Mock specimen mimicking Citrine/Sulfur)
Citrus x limon
Organic (Biological specimen)
Quartz Vein in Sedimentary Matrix
Silicon Dioxide (SiO2) with host rock
mineral
Epidote
Epidote - Ca2(Al2,Fe3+)3(SiO4)3(OH)
mineral
Shale
Fissile mudstone (primarily clay minerals and silt-sized quartz)
sedimentary
Carved Mottled Greenish-Yellow Crystal/Glass Object
Unknown; possibly a form of quartz (chalcedony/jadeite/nephrite) or glass/resin.
Man-made Object/Uncertain Mineral
Olivine (Peridot)
Magnesium Iron Silicate (Mg, Fe)2SiO4
Mineral
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2 with inclusions)
metamorphic
Sandstone Concretion with Fossil Wood
Ferruginous Sandstone Concretion (SiO2 with Fe2O3 cement)
sedimentary
Chert with Quartz Veining
Silicon Dioxide (SiO2)
sedimentary
Moss Agate
Silicon Dioxide with inclusions (SiO2 + Fe/Mn/Mg)
mineral
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
mineral
Mixed Quartz and Jasper Pebbles
Silicon Dioxide (SiO2)
Mineral