Chalcedony (Common Opal variant)
Silicon dioxide (SiO2) with varying levels of hydration
Category
Browse mineral (silicate replaced organic material) specimens identified by the Rock Identifier community.
Chalcedony (Common Opal variant)
Silicon dioxide (SiO2) with varying levels of hydration
Green Moss Agate
Agate (Silicon Dioxide, SiO2) with inclusions
Silicon
Element Si
Tiger's Eye
Silicon dioxide (SiO2) - Pseudomorph after crocidolite
Rough Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
Blue Apatite
Calcium Phosphate (Ca5(PO4)3(F,Cl,OH))
Pyrite in Matrix (Fool's Gold)
Iron Disulfide (FeS2)
Orange Calcite
Calcium Carbonate (CaCO3)
Coral (Precious Coral)
Corallium rubrum (Red Coral), Paracorallium japonicum (Momo Coral), Pleurocorallium elatius (Sardinian Coral), various other species within the Corallidae family. Chemically, it's primarily Calcium Carbonate (CaCO 3 ).
Sandstone (Ferruginous)
Arenite (Fe2O3 rich)
Anthracite Coal
Anthracite
Schist
Mica Schist
Milky Quartz
Quartz (Silicon Dioxide - SiO2)
Fire Opal (in matrix)
Hydrated Silica (SiO2·nH2O)
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxides)
Moss Agate
Chalcedony (Silicon Dioxide, SiO2) with inclusions
Tree Agate
Dendritic Agate (Silicon Dioxide, SiO2 with chlorite inclusions)
Moss Agate
Silicon Dioxide (SiO2) with Chlorite/Oxide inclusions
Conglomerate
Conglomerate
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Amber
Succinite (with a generalized formula of C10H16O)
Sandstone
Arenite
Soapstone
Steatite (primarily composed of Talc, Mg₃Si₄O₁₀(OH)₂)
Libyan Desert Glass
Impactite (vitreous silica), SiO2
Amazonite
K(AlSi3O8) - Potassium Aluminum Silicate (variety of Microcline)
Moonstone
Orthoclase (Potassium Aluminum Silicate, KAlSi3O8) with inclusions of Albite
Chalcedony (Agate Pebble)
Silicon Dioxide (SiO2)
Asphalt (Bituminous Concrete)
Composite material (bitumen binder with mineral aggregate)
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2 with inclusions of iron oxide)
Jasper
Silicon dioxide (SiO2) with impurities
Garnet
Garnet Group (Silicate mineral); general formula X3Y2(SiO4)3
Raw Emerald in Matrix
Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2 with inclusions of Iron Oxide)
Arfvedsonite with Garnet
Na3(Fe2+,Mg)4Fe3+Si8O22(OH)2
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
Natural White Pearl
Calcium Carbonate (Aragonite/Calcite) with Conchiolin - CaCO3
Tiger's Eye
Tiger's Eye (a variety of Chalcedony, which is cryptocrystalline quartz). Chemical Formula: SiO2 with inclusions of crocidolite fibers.
Sandstone
Arenite (primarily SiO2 with Fe2O3)
Sandstone
Arenite
Sandstone
Arenite (primarily SiO2)
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)