Moss Agate
Chalcedony (SiO2) with inclusions of manganese or iron oxide
Category
Browse organic gemstone (sedimentary associations) specimens identified by the Rock Identifier community.
Moss Agate
Chalcedony (SiO2) with inclusions of manganese or iron oxide
Pyrite
Pyrite (Iron sulfide, FeS₂)
Amber
Succinicum (Organic polymer, largely C10H16O)
Precious Red Coral
Corallium rubrum (Calcium Carbonate, CaCO3)
Greenstone / Serpentinite
Serpentinite (composed largely of Serpentine group minerals, Mg3Si2O5(OH)4)
Larimar
Blue Pectolite (NaCa2Si3O8(OH))
Chert (and Chalcedony)
Microcrystalline Quartz (SiO2)
Shale
Mudstone (composed primarily of clay minerals like kaolinite, illite, and smectite, with quartz and calcite)
Serpentinite
Serpentinite (composed primarily of Serpentine group minerals like Antigorite, Lizardite, and Chrysotile)
Lapis Lazuli
Lazurite-rich metamorphic rock
Pyrite
Iron Sulfide (FeS2)
Fluorite
Fluorite (Calcium Fluoride - CaF2)
Shungite
Non-crystalline carbonoid (Shungite)
Amethyst Quartz
SiO2 (Silicon Dioxide)
Fossiliferous Limestone with Rugose Coral
Calcite (CaCO3) matrix containing Rugosa (order of extinct solitary and colonial corals)
Chert (Jasper variation)
Chert (SiO2)
Amber (Dark/Black Variety)
Succinite (Resinite), C10H16O
Fluorite
Fluorite (Calcium Fluoride, CaF2)
Leopardskin Jasper
Jasper (a variety of microcrystalline Quartz)
Pearl
Calcium Carbonate (CaCO3) - Aragonite/Calcite
Chrysoprase
Chrysoprase (a variety of Chalcedony, SiO₂)
Azurite Geode
Azurite (Cu3(CO3)2(OH)2)
Chrysocolla on Quartz with Iron Oxides
Cu2-xAlx(H2-xSi2O5)(OH)4·n(H2O)
Ferruginous Quartz
Iron-stained Quartz (Silicon Dioxide + Fe2O3 / FeO(OH))
Coal (most likely Bituminous or Anthracite)
Coal (organic sedimentary rock)
Rose Quartz
Silicon Dioxide (SiO2) containing trace amounts of titanium, iron, or manganese
Jasper
Silicon dioxide (SiO2)
Chert (Flint nodule)
Chert (SiO2)
Coal (likely Bituminous or Lignite)
Organic Sedimentary Rock (Carbonaceous)
Amber
Succinite
Amber
Succinite (C10H16O)
Moss Agate
Chalcedony (Silicon Dioxide - SiO2) with inclusions
Malachite or Chrysocolla on Host Rock
Cu2(CO3)(OH)2 (Malachite) or (Cu,Al)2H2Si2O5(OH)4 (Chrysocolla)
Azurite
Azurite (Cu3(CO3)2(OH)2)
Azurite
Azurite (Cu3(CO3)2(OH)2)
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Pearl (with Peridot)
Calcium carbonate (CaCO3) + Conchiolin; Peridot: Magnesium iron silicate (Mg, Fe)2SiO4
Rhyolite
Rhyolite (felsic extrusive igneous rock)
Quartz (Citrine variety)
Silicon Dioxide (SiO2)
Quartz with Iron Staining
Silicon Dioxide (SiO2) with iron oxide impurities
Milky Quartz
Silicon Dioxide (SiO2)
Black Pearl (Tahitian-style Cultured Pearl)
Calcium Carbonate (Aragonite) with Conchiolin (CaCO3)