Sandstone
Arenite (SiO2 based typically)
Category
Browse man made object (coin) specimens identified by the Rock Identifier community.
Sandstone
Arenite (SiO2 based typically)
Rough Diamond
Diamond (pure Carbon, C)
Chert / Flint
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Green Aventurine
Silicon Dioxide (SiO2) with inclusions of Fuchsite
Aventurine
Silicon Dioxide (SiO2) with inclusions of Fuchsite
Fossilized Shell in Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
Coquina
Coquina (Bioclastic Limestone)
Red Sandstone
Arenite (with Iron Oxide / Hematite staining)
Amber
Succinite (fossilized resin)
Carnelian
Carnelian (a variety of Chalcedony, SiO ₂)
Nephrite Jade
Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2)
Moqui Marble (Iron-Oxide Concretion)
Iron Oxide Concretion (Fe2O3)
Amethyst
Amethyst (Silicon Dioxide, SiO2)
Aventurine (likely Green Aventurine)
Silicon Dioxide (SiO2) with mineral inclusions
Amazonite
Potassium Feldspar (Microcline), K(AlSi3O8)
Carnelian
Carnelian (a variety of Chalcedony, SiO₂)
Basalt
Basalt (comprising Plagioclase feldspar, Pyroxene, and Olivine)
Obsidian
Obsidian (Volcanic Glass)
Banded Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
Amethyst (Digital/Conceptual Representation)
Amethyst (Silicon Dioxide with iron impurities, SiO2)
Red Moss Agate (Jasper)
Silicon Dioxide (SiO2) with Iron Oxide inclusions
Amazonite
Potassium Feldspar (Microcline) - KAlSi3O8
Yellow Jade (Nephrite)
Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2)
Tiger's Eye (Multicolor/Variegated)
Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxides)
Amazonite
Potassium Feldspar (KAlSi3O8)
Amethyst
Silicon dioxide with iron impurities (SiO2)
Satin Spar (Selenite variant)
Gypsum (Calcium Sulfate Dihydrate, CaSO4·2H2O)
Green Jasper
Silicon Dioxide (SiO2) with mineral inclusions
Turquoise
Hydrated copper and aluminum phosphate (CuAl6(PO4)4(OH)8·4H2O)
Banded Calcite (often sold as 'Green Onyx')
Calcite (Calcium Carbonate, CaCO3)
Rhodonite
Rhodonite (Manganese Iron Magnesium Calcium Silicate - (Mn,Fe,Mg,Ca)SiO3)
Lapis Lazuli
Lapis lazuli (primary mineral: Lazurite, (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)
Malachite
Malachite (Copper Carbonate Hydroxide, Cu2CO3(OH)2)
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
Obsidian (Black Obsidian)
Obsidian (Volcanic Glass)
Lapis Lazuli
Lapis Lazuli (A metamorphic rock primarily composed of Lazurite: (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)
Chert (often called Flint)
Chert (Cryptocrystalline Quartz, SiO2)
Banded Calcite (often marketed as 'Mexican Onyx')
Calcite (Calcium Carbonate, CaCO3)
Green Onyx (Banded Calcite)
Calcite (Calcium Carbonate, CaCO3)
Smoky Quartz Cluster
Smoky Quartz (Silicon Dioxide - SiO2)
Milky Quartz (Micro-specimen)
Silicon Dioxide (SiO2)
Coquina
Coquina (Biogenic Limestone / CaCO3)