Chert (specifically Flint or Jasper variant)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Category
Organic Gemstone (Not A Rock Or Mineral In The Traditional Sense, But Bio Mineralized Material)
Browse organic gemstone (not a rock or mineral in the traditional sense, but bio mineralized material) specimens identified by the Rock Identifier community.
Quartz
SiO₂ (Silicon Dioxide)
Mineral
Gemstone Sand (Mineral Assortment)
Mixed Mineral Concentrates (Commonly including Quartz SiO2, Garnet X3Y2(SiO4)3, and Tourmaline (Na,Ca)(Li,Mg,Al)3(Al,Fe,Mn)6(BO3)3(Si6O18)(OH,F)4)
mineral
Diamond (as set in a metal alloy ring)
Diamond (Pure Carbon, C)
mineral
Pearl (with Peridot)
Calcium carbonate (CaCO3) + Conchiolin; Peridot: Magnesium iron silicate (Mg, Fe)2SiO4
mineral
Serpentinite (often containing Jadeite/Nephrite)
Antigorite-rich Serpentine Rock, (Mg, Fe)3Si2O5(OH)4
metamorphic
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Amber
Fossilized tree resin (not a true mineral as it is organic and amorphous); Chemical formula is highly variable, but often approximated as C10H16O.
Mineral
Chert (specifically Flint or Jasper variant)
Microcrystalline Quartz (SiO2)
sedimentary
Chert / Flint
Chert (varieties include Flint)
Sedimentary
Black Pearl (Tahitian Pearl)
Aragonite / Calcite (CaCO3) with Conchiolin
mineral
Shale
Shale (clastic sedimentary rock)
Sedimentary
Gravel or Crushed Stone
Fragmented Aggregate Stone
sedimentary or igneous fragment
Black Freshwater Pearls
Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3
mineral
Quartz (Milky or Clear variety)
Silicon Dioxide (SiO2)
mineral
Nuummite
Nuummite (Orthorhombic amphiboles: Anthophyllite and Gedrite)
metamorphic
Petrified Wood
Silicified Wood (SiO2 - Quartz/Chalcendony replacing organic matter)
sedimentary
Petrified Wood
Silicified Wood (primarily SiO2)
sedimentary
Nacre (Mother of Pearl)
Nacre (Biogenic Aragonite/Calcite composite, CaCO3)
mineral
Moss Agate
Silicon Dioxide (SiO2) with inclusions of manganese or iron oxides
Mineral (Variety of Chalcedony)
Petrified Wood
Siliconized Wood (SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
mineral
Amber
Succinite (Fossilized Tree Resin)
mineraloid
Chert (Brown variety / Common Jasper)
Microcrystalline Quartz (SiO2)
sedimentary
Quartzite with inclusions
Quartzite
metamorphic
Schist
Lepidoblastic Mica Schist
metamorphic
Pyrite Geode
Iron Disulfide (FeS2)
mineral
Petrified Wood
Silicified Wood (primarily SiO2)
sedimentary
Megalodon Shark Tooth (Partial Fossil)
Otodus megalodon (fossilized in Calcium Phosphate/Apatite)
Mineral/Fossil
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Chert (Jasper/Limonitic Chert)
Microcrystalline Quartz (SiO2)
sedimentary
Turquoise
Hydrated phosphate of copper and aluminium - CuAl6(PO4)4(OH)8·4H2O
mineral
Pyrite
Iron Sulfide (FeS2)
mineral
Fossilized Shark Tooth
Scapanorhynchus (Sand Tiger Shark relative)
sedimentary
Petrified Wood
Silicified Wood (primarily SiO2)
sedimentary
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)
Amethyst Geode
Amethyst (Silicon Dioxide), Formula: SiO2
mineral
Petrified Wood
Silicified wood (SiO2 - Silicon Dioxide)
sedimentary
Jade (Nephrite or Jadeite)
Nephrite (Ca2(Mg,Fe)5Si8O22(OH)2 - a variety of actinolite, an amphibole mineral); Jadeite (Na(Al,Fe3+)Si2O6 - a pyroxene mineral)
Metamorphic rock (for both Nephrite and Jadeite)
Shale or Argillite
Shale (sedimentary) / Argillite (metamorphic)
Sedimentary or Metamorphic (low-grade)
Sandstone
Clastic sedimentary rock (primarily SiO2)
sedimentary
Botryoidal Malachite
Malachite - Cu2CO3(OH)2
mineral