Chert (Gray Chalcedony)
Microcrystalline Quartz (SiO2)
Category
Browse organic gemstone (sedimentary associations) specimens identified by the Rock Identifier community.
Chert (Gray Chalcedony)
Microcrystalline Quartz (SiO2)
Pink Coral
Corallium rubrum (Calcium Carbonate, CaCO3)
Chert (Jasper/Flint variant)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Amber
Succinit (C10H16O)
Polished brecciated quartz specimen
Quartz (SiO₂), likely with iron-oxide staining and minor associated minerals
Carnelian (Orange Chalcedony)
Silicon Dioxide (SiO2)
Pyrite (Iron Pyrite) with Goethite Oxidation
Iron Sulfide (FeS2)
Chert (specifically Jasper or Flint type)
Microcrystalline Quartz (SiO2)
Chert (Chalcedony/Agate)
Microcrystalline Quartz (SiO2)
Polished ruby-in-zoisite (anyolite), likely
Ruby-bearing zoisite: zoisite Ca₂Al₃(SiO₄)₃(OH), with corundum Al₂O₃ and commonly amphibole
Chert (Flint)
Silicon Dioxide (SiO2)
Weathered, quartz-rich metamorphic rock (likely schist or gneiss)
Quartz–feldspar–mica schist/gneiss, with surface lichens and iron-oxide staining
Chert (Field Flint)
Microcrystalline Quartz (SiO2)
Lapis Lazuli (Lazurite crystals on Marble)
Lazurite / (Na,Ca)8[(S,Cl,SO4,OH)2|(AlSiO4)6]
Pearl
Calcium Carbonate (Aragonite/Calcite) with Conchiolin, CaCO3
Chert (Green variety)
Microcrystalline Opaline/Quartz (SiO2)
Chert (Quartz Variety)
Microcrystalline Silica (SiO2)
Pyrite
Iron Sulfide (FeS2)
Chert / Flint
Silicon Dioxide (SiO₂)
Chert (variations include Flint or Jasper)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Precious Coral
Corallium rubrum (Calcium carbonate with trace carotene)
Chert (Nodule)
Microcrystalline Quartz (SiO2)
Precious Red Coral
Corallium rubrum / Corallium japonicum
Chert (Agatized/Chalcedony variety)
Microcrystalline Quartz (SiO2)
Baltic Amber (Butterscotch or Egg Yolk Variety)
Succinite (chemical formula: C10H16O)
Amber
Succinite (Fossilized Tree Resin)
Amber
Succinite (fossilized resin)
Prehnite
Prehnite - Ca2Al(AlSi3O10)(OH)2
Amber
Fossilized Tree Resin
Fossiliferous Sandstone
Sedimentary rock containing invertebrate fossils
Turquoise and Red Coral
Turquoise: CuAl6(PO4)4(OH)8·4H2O; Red Coral: Corallium rubrum (organic gemstone)
Malachite
Copper carbonate hydroxide Cu2CO3(OH)2
Bornite
Copper Iron Sulfide (Cu5FeS4)
Black Tourmaline
Schorl (Sodium Iron Aluminum Borosilicate Hydroxide)
Chert (variations include Flint or Jasper)
Silicon Dioxide (SiO2)
Pyrite
Pyrite (Iron Disulfide), FeS2
Ironstone concretion / Limonitic Sandstone
Goethite/Hematite Cemented Sandstone (Hydrated Iron Oxide)
Chert (specifically Red Chert/Jasper variety)
Silicon Dioxide (SiO2)
Amber
Succinite (approximate formula C10H16O)
Turquoise and Spiny Oyster (Heishi style beads)
Turquoise (CuAl6(PO4)4(OH)8·4H2O) and Spondylus (Spiny Oyster shell)
Petrified Wood
Silicified Wood (SiO2)
Amber
Succinite (fossilized tree resin), C10H16O