Pearl (Pendant)
Calcium Carbonate (Aragonite/Calcite) - CaCO3
gemstone
Category
Organic Gemstone (Not A Mineral)
Browse organic gemstone (not a mineral) specimens identified by the Rock Identifier community.
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Jasper
Silicon Dioxide (Microcrystalline Quartz, $SiO_2$)
sedimentary
Fossil bivalve shell
Likely an extinct or modern-like ribbed cockle/scallop; exact genus requires locality and diagnostic hinge features
fossil
Amber
Succinite (specifically for Baltic amber); Chemical formula approximately C10H16O
mineral
Turquoise-and-coral silver jewelry brooch
Turquoise: hydrated copper aluminum phosphate, CuAl₆(PO₄)₄(OH)₈·4H₂O; red cabochons appear to be coral, likely set in silver
gemstone
Red Coral (Precious Coral)
Corallium rubrum (Calcium Carbonate, CaCO3)
sedimentary
Amber
Succinite (Formula: C10H16O)
mineral
Polished moss agate (likely dendritic agate)
Chalcedony, microcrystalline quartz (SiO₂), with inclusions of manganese/iron oxides or hornblende
gemstone
Tumbled amber
Fossilized plant resin; commonly succinite (C10H16O)
gemstone
Precious Coral
Corallium rubrum (Calcium Carbonate, CaCO3)
mineral
Obsidian
Obsidian (Volcanic Glass)
igneous
Bauxite
Bauxite (Al(OH)3, AlO(OH))
sedimentary
Wonderstone (Banded Rhyolite)
Rhyolite (Silicon Dioxide with Iron Oxide impurities)
igneous
Obsidian
Volcanic glass (SiO2 + impurities)
igneous
Slag Glass
Vitreous Silicate Residue
industrial byproduct (anthropogenic rock)
Bauxite
AlOx(OH)3-2x (mixture of Gibbsite, Boehmite, and Diaspore)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
mineral
Rainbow Fluorite
Fluorite (Calcium Fluoride, CaF2)
mineral
Moss Agate
Silicon Dioxide (SiO2) with inclusions of Manganese or Iron oxides
mineral
Amber
Succinite (fossilized resin, C10H16O)
mineral
Amber
Succinite (approximate formula C10H16O)
mineral
Dyed Agate (Tumbled)
Silicon Dioxide (Chalcedony variety, artificially dyed)
gemstone
Blue Apatite
Apatite - Ca5(PO4)3(F,Cl,OH)
mineral
Turquoise, Pearl, and Coral Necklace
CuAl6(PO4)4(OH)8·4H2O (Turquoise) / CaCO3 (Pearl and Coral)
mineral
Gold Sheen Obsidian
Volcanic Glass (SiO2 + impurities)
igneous
Lapis Lazuli (Tumbled Specimen)
Lapis Lazuli (Aggregate rock containing Lazurite: (Na,Ca)8(AlSiO4)6(SO4,S,Cl)2)
metamorphic
Pink Opal
Hydrated silica (SiO2 "n H2O)
mineral
Limonite / Ironstone
FeO(OH)·nH2O
sedimentary
Plume Agate
Cryptocrystalline Quartz (SiO2)
Mineral/Gemstone
Moss Agate and Hematite
Silica (SiO2) with fibrous inclusions of Manganese or Iron; Hematite (Fe2O3)
mineral
Mookaite Jasper
Silicon Dioxide with Iron Oxide impurities (SiO2)
mineral
Yellow-brown translucent mineral fragment, likely citrine or amber
Quartz (SiO₂), if citrine; succinite (fossil resin), if amber
mineral
Amber
Succinite (C10H16O)
mineral
Pearl
Calcium carbonate (CaCO3) in the form of aragonite
gemstone
Raw amber
Amber (fossilized plant resin; commonly succinite, C10H16O)
gemstone
Amber
Fossilized Tree Resin
gemstone
Limonite / Ironstone
Hydrated Iron Oxide (FeO(OH)·nH2O)
sedimentary
Picture Jasper
SiO2
mineral
Amber
Succinite (Resinous fossilized tree sap)
Mineraloid
Limonite (Iron Ore)
Limonite (Hydrated Iron Oxide, FeO(OH)·nH2O)
Mineral
Tumbled serpentine (likely bowenite/antigorite)
Serpentine-group minerals, chiefly antigorite or lizardite; commonly Mg₃Si₂O₅(OH)₄
metamorphic
Obsidian
Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)
igneous