Greisen
Greisen
Category
Browse mineral like byproduct (technogenic) specimens identified by the Rock Identifier community.
Greisen
Greisen
Vesicular Basalt (Lava Rock)
Aphanitic Mafic Igneous Rock
Concrete with Aggregate
Composite construction material; primary matrix is Calcium Silicate Hydrate (C-S-H)
Fluorite
Calcium Fluoride (CaF2)
Mixed collection of Quartz varieties, Chalcedony, and metamorphic pebbles
Mixed gemstones (primarily Silicon Dioxide - SiO2)
Dendritic Agate (Tumbled)
Silicon Dioxide (SiO2) with Manganese/Iron oxide inclusions
Turquoise with Pyrite
Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O] with Iron Pyrite (FeS2)
Sandstone
Clastic Sedimentary Rock (composed primarily of Quartz: SiO2)
Red Sandstone
Clastic sedimentary rock (primarily SiO2 with Fe2O3 iron oxide staining)
Biotite or Phlogopite Mica
K(Mg,Fe)3(AlSi3O10)(F,OH)2
Dyed Quartz (often sold as 'Blue Quartz' or 'Blue Agate')
Silicon Dioxide (SiO2) with artificial pigment
Ferruginous Sandstone (Gritstone)
Arenite with Iron-Oxide Cement (SiO2 with Fe2O3 and FeO(OH))
Turquoise
Turquoise - CuAl6(PO4)4(OH)8·4H2O (Hydrous phosphate of copper and aluminium)
Watermelon Tourmaline in Quartz Matrix
Elbaite (complex Borosilicate) - Na(Li,Al)3Al6(BO3)3Si6O18(OH)4
Iron-stained Quartz
Silicon Dioxide (SiO2) with Limonite/Hematite inclusions
Granite
Granite (Felsic Plutonic Rock)
Sandstone
Arenite (primarily composed of SiO2)
Red Sandstone
Clastic Terrigenous Sedimentary Rock (composed mostly of SiO2 with Fe2O3)
Red Sandstone
Arenite (predominantly Quartz with Hematite cementation)
Mica Schist
Mica Schist (primarily Muscovite and Quartz)
Obsidian
Obsidian (Volcanic Glass)
Limonite (Iron Ore/Sandstone mixture)
Limonite (FeO(OH)·nH2O) often mixed with Goethite and sedimentary matrix
Brown Sandstone
Arenite (primarily Quartz and Feldspar, with Iron Oxide cement)
Muscovite Mica
Muscovite (KAl2(AlSi3O10)(OH)2)
Vesicular Basalt with Secondary Mineral Inclusions
Aphanitic Mafic Igneous Rock (primarily Plagioclase and Pyroxene)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Green Jasper
Jasper (Silicon Dioxide, SiO2)
Orthoclase Feldspar
KAlSi3O8 (Potassium Aluminum Silicate)
Native Copper
Native Copper (Cu)
Granite / Gneiss Complex
Felsic Plutonic Rock (Granite) or High-grade Metamorphic Rock (Gneiss)
Obsidian
Obsidian (Amorphous volcanic glass, predominantly SiO2)
Dendritic Agate
Silicon Dioxide (SiO2) with inclusions
Granite
Granite
Yellow Aventurine (specifically a carved crescent moon)
Silicon Dioxide (SiO2) with inclusions
Sandstone (with Iron Staining)
Clastic sedimentary rock (primarily SiO2)
Septarian Nodule (Dragon Stone)
Septarian Concretion (CaCO3 with Siderite and Calcite)
Geode (Quartz)
Silicon Dioxide (SiO2)
Biotite Mica
K(Mg, Fe)3AlSi3O10(F, OH)2
Amygdaloidal Basalt
Basalt with secondary mineral infilling
Tree Agate (Dendritic Agate)
Silicon Dioxide (SiO2) with Manganese/Iron inclusions
Bauxite
Bauxite (Al(OH)3, AlO(OH))
Obsidian
Volcanic glass