Olivine-bearing Basalt / Scoria
Mafic Igneous Rock (primarily (Mg, Fe)2SiO4)
Category
Browse industrial byproduct (often mistaken for obsidian or mineral) specimens identified by the Rock Identifier community.
Olivine-bearing Basalt / Scoria
Mafic Igneous Rock (primarily (Mg, Fe)2SiO4)
Corundum (Sapphire/Ruby in Matrix)
Aluminium oxide (Al2O3)
Olivine in Basalt (Peridot)
Magnesium Iron Silicate (Mg,Fe)2SiO4 (Mineral) within Basalt (Rock)
Red Sandstone
Arenite (with Iron Oxide / Hematite), Formula: SiO2 (Quartz) + Fe2O3 (Hematite coating)
Satin Spar (Selenite)
Gypsum (CaSO4·2H2O)
Quartz (River Pebble)
Silicon Dioxide (SiO2)
Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
Blue Apatite
Chlorapatite / Fluorapatite (Ca5(PO4)3(F,Cl,OH))
Sandstone (likely Iron-rich or Arkosic)
Arenite (SiO2 with FeO(OH) or Fe2O3 staining)
Fluorite (often called Rainbow Fluorite or Purple-Green Fluorite)
Calcium Fluoride (CaF2)
Chalcedony (specifically Agate or Common Opal variety)
Cryptocrystalline Silica (SiO2)
Rough Garnet (Almandine)
Almandine Garnet (Fe3Al2(SiO4)3)
Grey Agate
Silicon Dioxide (SiO2) - variety: Agate/Chalcedony
Yellow Calcite
Calcite (Calcium Carbonate, CaCO3)
Obsidian (in jewelry setting)
Volcanic Glass (Amorphous Silica)
Milky Quartz (Quartz Vein)
Silicon Dioxide (SiO2)
Red Sandstone
Arenite (Ferruginous Sandstone)
Olivine (Peridot in gem form)
Magnesium Iron Silicate (Mg,Fe)2SiO4
Milky Quartz in Matrix
Silicon Dioxide (SiO2)
Granitic Pegmatite
Pegmatite (Quartz: SiO2, Feldspar: KAlSi3O8, Mica: KAl2(AlSi3O10)(OH)2)
Milky Quartz
Silicon Dioxide (SiO2)
Rough Star Sapphire (Corundum)
Al2O3 (Aluminum Oxide)
Magnetite
Magnetite (Iron(II,III) oxide, Fe3O4)
Diamond (Cluster Setting)
Carbon (C) - Diamond
Banded Sandstone (Differential Weathering)
Clastic Sedimentary Rock (primarily SiO2)
Chert / Yellow Jasper
Silicon Dioxide (SiO2)
Rose Quartz and Milky Quartz
Silicon Dioxide (SiO2)
Kyanite (Green and Blue varieties)
Kyanite (Al2SiO5)
Quartz (Iron-stained)
Silicon Dioxide (SiO2)
Quartz with Hematite Inclusions
Silicon Dioxide (SiO2) with Ferric Oxide (Fe2O3)
Quartz (specifically Citrine or Iron-stained Quartz)
Silicon Dioxide (SiO2)
Orange Calcite
Calcium Carbonate (CaCO3)
Fluorite
Calcium fluoride (CaF2)
Sodalite
Sodalite - Sodium Aluminum Silicate Chloride (Na8(Al6Si6O24)Cl2)
Chert (Chalcedony/Agate variety)
Silicon Dioxide (SiO2)
Aragonite / Calcite Geode
Calcium Carbonate (CaCO3)
Quartz (River Pebble)
Silicon Dioxide (SiO2)
Diamond
Native Carbon (C)
Limonite (Iron Ore)
FeO(OH)·nH2O (Hydrous ferric oxide)
Yellow Quartz / Quartz Pebble
Silicon Dioxide (SiO2)
Barite Rose on Marcasite
Barium Sulfate (BaSO4) on Iron Sulfide (FeS2)
Milk Quartz (Tumbled)
Silicon Dioxide (SiO2)