Petrified Wood
Silicified Wood (SiO2 as Quartz/Chert/Chalcedony)
Category
Browse organic mineraloid and mineral specimens identified by the Rock Identifier community.
Petrified Wood
Silicified Wood (SiO2 as Quartz/Chert/Chalcedony)
Moss Agate
Silicon Dioxide with inclusions (SiO2 + impurities)
Pearl
Organic gemstone (Calcium carbonate / CaCO3 + Conchiolin)
Moss Agate
Silicon Dioxide (SiO2) with inclusions of Manganese or Iron oxide
Pyrite Geode
Iron Disulfide (FeS2)
Amber (Rough)
Amber (Fossilized Tree Resin, succinite)
Moss Agate
Cryptocrystalline Quartz (SiO2 with Manganese or Iron Oxide inclusions)
Turquoise and Red Coral
Turquoise: CuAl6(PO4)4(OH)8·4H2O; Red Coral: Corallium rubrum (organic gemstone)
Chert with Iron Oxide Staining
Microcrystalline Quartz (SiO2) with Limonite/Goethite staining
Petrified Wood
Silicified wood (Quartz/Chalcedony replacement of cellulose)
Petrified Wood
Silicified Wood (SiO2)
Nacre (Mother of Pearl)
Nacre (Biogenic Aragonite/Calcite composite, CaCO3)
Sandstone
Arenite (SiO2 based)
Druzy Chalcedony/Quartz on Fluorite core
Silicon Dioxide (SiO2) on Calcium Fluoride (CaF2)
Petrified Wood
Silicified Wood (SiO2)
Pyrite
Iron Sulfide (FeS2)
Tufa (Limestone)
Calcareous Tufa (CaCO3)
Amber Inlay Jewelry
Fossilized Resin (C10H16O)
Goldstone (Brown)
Aventurine glass
Baroque Pearl
Biogenic Calcium Carbonate (Aragonite/Conchiolin)
Petrified Wood
Silicified wood (Quartz, Chalcedony, or Opal)
Petrified Wood
Silicified wood (Quartz, SiO2)
Petrified Wood
Silicified Wood (SiO2)
Dendritic Agate (or Dendritic Opal)
SiO2 (for Agate), SiO2·nH2O (for Opal)
Petrified Wood
Silicified wood (primarily SiO2)
Chert (Jasper)
Silicon Dioxide (SiO2)
Glauconite (Greensand)
(K, Na)(Fe3⁰, Al, Mg)₂(Si, Al)₄O₁₀(OH)₂
Chert (Nodule)
Silicon Dioxide (SiO2)
Fossilized Crab Carapace (Concretion)
Decapoda (fossil), typically preserved in calcite or siderite concretion
Moqui Marbles
Iron Oxide Concretion (Hematite/Goethite)
Petrified Wood
Silicified wood (primarily SiO2)
Fossilized Tiger Shark Tooth
Galeocerdo cuvier (fossilized hydroxylapatite)
Chert (Flint/Chalcedony)
Microcrystalline Quartz (SiO2)
Chert (often called Jasper in this color variety)
Microcrystalline Quartz (SiO2)
Chert / Flint
Microcrystalline or cryptocrystalline quartz (SiO2)
Moss Agate
Silicon dioxide (SiO2) with inclusions
Green Sandstone
Glauconitic Sandstone
Chert with Quartz/Calcite Vein
Microcrystalline Silica (SiO2)
Chert / Flint
Chert (SiO2)
Shungite
Non-crystalline carbon (allotrope of carbon)
Amber
Succinite (fossilized resin)
Moss Agate
Chalcedony (Silicon Dioxide) with dendritic inclusions (SiO2)