Agate
Silicon Dioxide (SiO2) - variety of Chalcedony
mineral
Category
Industrial Byproduct (Often Confused With Igneous Rocks Or Meteorites)
Browse industrial byproduct (often confused with igneous rocks or meteorites) specimens identified by the Rock Identifier community.
Lazulite
Lazulite (MgAl2(PO4)2(OH)2)
mineral
Orange Calcite
Calcite (CaCO3)
Mineral
Yellow Quartz (Citrine or Yellow Chalcedony)
Silicon Dioxide (SiO2)
mineral
Labradorite
Labradorite (Plagioclase Feldspar Series) - (Ca, Na)(Al, Si)4O8
mineral
Green Fluorite (Beaded)
Fluorite (Calcium Fluoride, CaF2)
mineral
Pegmatite (White Granite variant)
Pegmatitic Granite (Quartz and Feldspar rich)
igneous
Garnetiferous Quartzite (Garnet Gneiss Pebble)
Garnet-bearing Quartzite or Quartz-Feldspar Gneiss
metamorphic
Red Garnet (Pyrope or Almandine)
Garnet Group (A3B2(SiO4)3)
mineral
Quartz with Iron Stains
Quartz (SiO2) with iron oxide/hydroxide staining
Mineral
Granite (Phaneritic Igneous Rock)
Granite
igneous
Scoria (Red Lava Rock)
Scoria (Vesicular Basalt/Andesite)
igneous
Cupronickel (on a 1981 Mexico 20 Pesos coin)
Copper-Nickel Alloy (Cu75Ni25)
mineral
Pyrite (Fool's Gold) Ore
Iron Disulfide (FeS2)
mineral
Rhodonite
Rhodonite (MnSiO3)
Mineral
Citrine
Silicon Dioxide (SiO2) with iron impurities
mineral
Rhodonite
Rhodonite (Manganese Silicate), (Mn,Fe,Mg,Ca)SiO3
mineral
Pyrite
Iron Pyrite (FeS₂)
Mineral
Quartz (River Pebble)
Silicon Dioxide (SiO2)
mineral
Garnet
Garnet Group (formula varies, e.g., Almasndine: Fe3Al2(SiO4)3)
mineral
Silicon
Silicon (Si)
mineral
Biotite Mica
K(Mg,Fe)3AlSi3O10(OH)2
Mineral in a matrix (likely quartz or feldspar)
Yellow Quartz / Quartzite Pebble
Silicon Dioxide (SiO2)
mineral
Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
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
Iron-Stained Quartz (Riverside Cobble)
Silicon Dioxide (SiO2) with Limonite/Hematite inclusions
mineral
Water and Silt (Sedimentary Environment)
Suspended Sediment / H2O (dihydrogen monoxide)
sedimentary
Ruby
Corundum (mineral species), variety: Ruby (Al2O3 with Cr3+ as the chromophore)
Mineral
Biotite Mica
Biotite, K(Mg,Fe)3AlSi3O10(F,OH)2
mineral
Sapphire
Corundum (Al₂O₃) with trace elements causing color variations.
Mineral
Black Star Diopside
Diopside (CaMgSi2O6) with Magnetite inclusions
mineral
Garnet (Red Garnet)
Garnet Group. The red varieties seen in jewelry are typically Almandine (Fe3Al2(SiO4)3), Pyrope (Mg3Al2(SiO4)3), or a mix of the two (pyrope-almandine series).
Mineral (specifically, a variety of the mineral species Pyrope-Almandine Garnet)
Strawberry Quartz
Quartz (SiO₂) with Goethite (α-FeO(OH)) and/or Lepidocrocite (γ-FeO(OH)) inclusions
Mineral
Schist
Schist (various compositions)
metamorphic
Yellow Agate
Agate (Varietal form of Chalcedony/Quartz, SiO2)
mineral
Aquamarine on Feldspar Matrix
Beryl (Be3Al2Si6O18) with Potassium Feldspar (KAlSi3O8)
mineral
Jasper, Agate, Quartz Mix (Polished Beads)
SiO₂ (Silicon Dioxide) for Quartz. Jasper and Agate are cryptocrystalline varieties of Quartz.
Mineral/Semiprecious Gemstone (variety of Quartz)
Pyrite
Iron Sulfide (FeS2)
mineral
Ruby
Corundum (Al2O3 with Chromium traces)
mineral
Quartz (River Pebble)
Silicon Dioxide (SiO2)
mineral
Ruby in Matrix
Corundum (Al2O3)
mineral
Ruby and Diamond Heart Pendant
Corundum (Al2O3) and Diamond (C)
mineral