Amethyst (variety of Quartz)
SiO2 (Silicon Dioxide) with trace iron impurities
Mineral
Category
Industrial By Product
Browse industrial by product specimens identified by the Rock Identifier community.
Sandstone
Sandstone (clastic sedimentary rock)
Rock
Amethyst
Quartz (SiO2) with trace iron impurities
Mineral
Opal
Hydrous silicon dioxide (SiO2·nH2O)
mineral
Calcite (commonly referred to as Orange Calcite or Honey Calcite given its color)
Calcite
Mineral
Diamond
Diamond (C)
Mineral
Blue Kyanite
Kyanite (Al2SiO5)
mineral
Amazonite
KAlSi3O8 (Potassium Feldspar, variety of Microcline)
Mineral
Magnetite
Magnetite (Fe3O4)
Mineral
Sapphire (Corundum)
Corundum (Al2O3), variety Sapphire
Mineral
Rough Green Fluorite
Fluorite (Calcium Fluoride - CaF2)
mineral
Schist
Schist (various compositions)
metamorphic
Corundum
Corundum (Al2O3)
Mineral
Emerald
Beryl (Be3Al2Si6O18), specifically the green variety colored by chromium or vanadium
Mineral (Gemstone variety of Beryl)
Yellow Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Green Calcite
Calcium Carbonate (CaCO3)
mineral
Pyrite
Iron Sulfide (FeS2)
mineral
Greenschist
Greenschist facies rock
Metamorphic
Chert
Chert (microcrystalline quartz, SiO2)
Sedimentary
Emerald
Beryl (Be₃Al₂Si₆O₁₈), specifically the green variety colored by trace amounts of chromium or vanadium.
Mineral
Epidote
Epidote Group (e.g., Clinozoisite, Epidote, Piemontite), Epidote formula: Ca2(Al,Fe)3(SiO4)3(OH)
Mineral
Ferruginous Quartz (Iron-stained Quartz)
Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions
mineral
Smoky Quartz (Chlorite Inclusions)
Silicon Dioxide (SiO2) with trace Aluminum and Natural Irradiation
mineral
Black Tourmaline
Schorl (NaFe3Al6(BO3)3Si6O18(OH)4)
mineral
Veined Pebble (likely a Quartz-Veined Pebble)
Pebble with Mineral Vein (e.g., Quartz Vein in a Chert/Mudstone Pebble)
Sedimentary Rock (possibly conglomerate or breccia with a quartz vein)
Red Jasper
Jasper (a variety of Quartz, SiO2)
Mineral
Black Tourmaline
Schorl (Sodium Iron Aluminum Borosilicate Hydroxide); NaFe2+3Al6(Si6O18)(BO3)3(OH)3(OH)
mineral
Orange Calcite (likely polished specimen)
Calcite
Mineral
Leopard Skin Jasper
Chalcedony (cryptocrystalline Quartz)
Mineral
Amethyst
SiO2 (Silicon Dioxide) - a variety of Quartz
Mineral
Aquamarine
Aquamarine (Beryl variety); Be3Al2Si6O18
mineral
Rutilated Quartz
Quartz (SiO2) with Rutile (TiO2) inclusions
Mineral
Sea Glass (White/Clear)
Amorphous Silica (Alkali-Lime-Silica Glass), SiO2 + Na2O + CaO
Anthropogenic (Man-made product subject to geological processes)
Aquamarine
Beryl (Be3Al2Si6O18 with iron impurities)
mineral
Fluorite (Purple Fluorite in Matrix)
Fluorite (Calcium Fluoride, CaF2)
mineral
Black Tourmaline
Schorl (Na(Fe²⁺)₃Al₆(OH)₄(BO₃)₃Si₆O₁₈)
mineral
Biotite Mica
Biotite, K(Mg,Fe)3AlSi3O10(F,OH)2
mineral
Pebble (likely Quartz or Chert)
SiO₂ (Silicon Dioxide) - referring to the likely main mineral composition, Quartz. If it's chert, the scientific name remains SiO₂ with a microcrystalline structure.
Sedimentary Rock
Peridot
Olivine (specifically, the gem-quality variety forsterite, (Mg,Fe)2SiO4)
Mineral
Chert (or possibly Flint)
SiO2 (Silicon Dioxide)
Sedimentary Rock
Quartz (vein quartz)
SiO2 (Silicon Dioxide)
Mineral
Turquoise
CuAl6(PO4)4(OH)8·4H2O
mineral