Chert / Flint
Chert (SiO2)
Category
Browse organic gemstone (often associated with sedimentary sequences) specimens identified by the Rock Identifier community.
Chert / Flint
Chert (SiO2)
Jasper
Silicon dioxide (SiO2)
Fluorite
Calcium Fluoride (CaF2)
Emerald in Matrix
Beryl (Be3Al2Si6O18) with Chromium impurities
Turquoise (Dyed Howlite/Magnesite)
CuAl6(PO4)4(OH)8·4H2O (Natural Turquoise) or Ca2B5SiO9(OH)5 (Howlite)
Rhodonite
Manganese Inosilicate (Mn,Fe,Mg,Ca)SiO3
Amber
Fossilized tree resin (Amorphous organic polymer)
Chert (Green Fossilized Algae or Jasper)
Silicon Dioxide (SiO2)
Rhodochrosite
Manganese Carbonate (MnCO3)
Milky Quartz with Iron Staining
Silicon Dioxide (SiO2)
Jasper (Chert / Chalcedony)
Silicon Dioxide (SiO2) with Iron Oxide inclusions
Weathered gray sandstone or siltstone cobble
Clastic sedimentary rock, likely quartz-rich sandstone/siltstone (diagnosis uncertain from image)
Serpentine (Serpentinite)
Mg3Si2O5(OH)4
Sandstone (Cross-bedded Drill Core)
Clastic Sedimentary Rock (primarily SiO2)
Native copper
Copper (Cu), often with malachite, cuprite, or matrix minerals
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
Sunstone
Plagioclase Feldspar (Na,Ca)(Si,Al)4O8
Pyrite
Pyrite (FeS2)
Shale
Shale
Rhodonite
Rhodonite (MnSiO3)
Carnelian
Silicon Dioxide (Chalcedony variety, SiO2)
Chert (and Jasper/Chalcedony variety)
Microcrystalline Quartz (SiO2)
Chert (often called Flint)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Jasper
Microcrystalline Quartz (SiO2)
Jasper
Microcrystalline quartz (SiO2)
Jasper
Microcrystalline Quartz (SiO2)
Jasper
Microcrystalline quartz, SiO2
Galena with Pyrite
Lead Sulfide (PbS) associated with Iron Sulfide (FeS2)
Menilite Opal (Goddess Stone)
Menilite Opalescent Silex (Amorphous Hydrated Silica)
Amethyst pendant
Amethyst, purple variety of quartz (SiO₂)
Yellow Sapphire
Corundum (Al2O3)
Rhodochrosite
Manganese Carbonate (MnCO3)
Ironstone concretion / Limonitic Sandstone
Goethite/Hematite Cemented Sandstone (Hydrated Iron Oxide)
Amber
Succinates (Fossilized Tree Resin)
Emerald
Beryl (Be3Al2(SiO3)6)
Amber
Succinite (fossilized resin)
Pink Coral
Corallium rubrum (Calcium Carbonate, CaCO3)
Red Coral (Precious Coral)
Corallium rubrum (Calcium Carbonate, CaCO3)
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
Red Jasper
Silicon Dioxide (SiO2) with Iron Oxide inclusions
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Chert (Iron-stained)
Microcrystalline silica (SiO2) with trace Iron oxide (Fe2O3)