Clear Quartz Crystal
Silicon Dioxide (SiO2)
Category
Browse sedimentary (chemically precipitated) or metamorphic specimens identified by the Rock Identifier community.
Clear Quartz Crystal
Silicon Dioxide (SiO2)
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
Emerald
Beryl (Be3Al2(SiO3)6) with Chromium and/or Vanadium impurities
Pyrite (on Quartz/Host Rock)
Iron Sulfide (FeS₂)
Hematite
Iron(III) oxide (Fe2O3)
Gneiss
Gneiss (Metamorphic rock of variable composition, typically SiO2 rich)
Dolomite
Dolomite (CaMg(CO3)2)
Iron-stained Quartz
Silicon Dioxide with Iron Oxide (SiO2 with Limonite/Hematite impurities)
Milky Quartz (Vein Quartz)
Silicon Dioxide (SiO2)
Malachite
Malachite (Cu2CO3(OH)2)
Ferruginous Quartz (Iron-stained Quartz)
Silicon Dioxide (SiO2) with Hematite/Limonite impurities
Ruby
Corundum (Al2O3 with Chromium traces)
Garnet Schist
Almandine-Muscovite Schist
Concrete
Anthropogenic Sedimentary Conglomerate (Cement mixture: typically Ca2SiO4, Ca3SiO5, Ca3Al2O6)
Gneiss
Gneiss (a type of metamorphic rock)
Epidote
{Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)
Red Jasper
Silicon Dioxide (SiO2) with Hematite impurities
Black Tourmaline (Schorl)
Schorl (Na(Fe^2+)3Al6(Si6O18)(BO3)3(OH)4)
Milky Quartz
Quartz (Silica / Silicon Dioxide), SiO2
Milky Quartz
Quartz (Silica / Silicon Dioxide, SiO2)
Emerald
Beryl (Be3Al2(SiO3)6) with Chromium/Vanadium impurities
Pyrite
Iron Disulfide (FeS2)
Orange Calcite
Calcium Carbonate (CaCO3)
Rhodochrosite
Manganese carbonate (MnCO3)
Amethyst
Quartz variety; chemical formula: SiO₂ (silicon dioxide) with Fe³⁺ impurities
Sandstone, Quartzite, and River Pebbles
Silicon Dioxide (SiO2) based Sedimentary/Metamorphic structures
Amber
Succinite (a Fossilized Tree Resin); Chemical formula is approximately C10H16O
Amethyst Geode
Amethyst (Silicon Dioxide), Formula: SiO2
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Greenschist
Greenschist facies rock
Quartz with Iron Staining
Quartz (Silicon Dioxide, SiO2)
Jasper (Iron-stained Chert)
Silicon Dioxide (SiO2)
Greenschist
Greenschist (Chlorite Schist)
Iron Meteorite Fragment
Siderite (Geological term for iron meteorite class - Fe/Ni alloy)
Epidote
Epidote - Ca2(Al,Fe)3(SiO4)3(OH)
Graphite-veined Quartzite
Meta-sedimentary Quartzite with Carbonaceous/Graphitic Inclusions (SiO2 + C)
Quartz (likely Jasper or Chert variety)
Quartz (SiO₂)
Jasper with Epidote Vein
Silicon Dioxide (SiO2) with Calcium Aluminum Iron Silicate (Ca2(Al,Fe)3(SiO4)3(OH))
Tourmaline (likely Schorl)
Tourmaline Group Mineral (e.g., Schorl for black varieties); (Na,Ca)(Li,Mg,Fe,Mn,Al)3Al6(BO3)3Si6O18(OH)4
Agate (Dyed High-Grade Polished Slice)
Silicon dioxide (SiO2), Chalcedony crystal variety
Gneiss
Gneiss
Pebble
Clast (specifically a granule or small pebble)