Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Category
Browse sedimentary (chemically precipitated mineral) specimens identified by the Rock Identifier community.
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Dark flint or chert fragment
Microcrystalline quartz (SiO₂), commonly called flint when dark and nodular
Red Jasper
Silicon Dioxide (SiO2) with iron inclusions
Chert (Flint) with Quartz Inclusions
Microcrystalline Quartz (SiO2)
Chert (Jasper/Flint variety)
Silicon Dioxide (SiO2)
Banded Iron Formation (Hematite/Magnetite-rich)
Banded Iron Formation (BIF)
Chert (variations include Flint/Jasper)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Fluorite Octahedron
Fluorite (Calcium Fluoride, CaF2)
Quartzite Pebble
Metamorphic Quartzite (SiO2)
Chert (Flint Nodular)
Chert (Silicon dioxide, SiO2)
Red Jasper
Silicon dioxide (Microcrystalline Quartz, $SiO_2$)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Agate Geode
Silicon dioxide (SiO2) - Chalcedony
Banded Chert / Flint Pebble
Microcrystalline Quartz (SiO2)
Chert Pebble (Yellow Jasper)
Microcrystalline Quartz (SiO2)
Milky Quartz (Beach Pebble)
Quartz (Silicon Dioxide, SiO2)
Dyed blue howlite (turquoise imitation), possibly dyed magnesite
Howlite: Ca₂B₅SiO₉(OH)₅; the vivid blue color is artificial dye. Exact identification is uncertain from the photograph alone.
Agate
Silicon Dioxide (SiO2) - Chalcedony
White Salt Crystal Lamp (Halite)
Halite (Sodium Chloride, NaCl)
Rough Topaz
Aluminum silicate fluoride hydroxide [Al2SiO4(F, OH)2]
Moss Agate
Silicon Dioxide (SiO2) with inclusions
Quartz Pebble
Silicon Dioxide (SiO2)
Blue Quartzite
Blue Quartzite (Primary mineral: Quartz, SiO2 with magnesio-riebeckite or crocidolite inclusions)
Quartz Vein / Quartzite with Iron Oxide Staining
Silicon Dioxide (SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Gneiss
Foliated quartzo-feldspathic gneiss, commonly containing biotite or amphibole
Milky Quartz
Silicon Dioxide (SiO2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Pink Amethyst Geode
Silicon Dioxide (SiO2) with Hematite/Iron impurities
Astrophyllite
Potassium Sodium Iron Manganese Titanium Silicate Hydroxide (K3NaFe7Ti2Si8O24(OH)7)
Quartzite (Yellow/Iron-stained Quartz)
Quartzite (primarily SiO2 with iron oxide impurities)
Agate
Silicon Dioxide (SiO2) - Chalcedony variety
Quartz (Water-worn pebble)
Silicon Dioxide (SiO2)
Quartz Pebble
Quartz (Silicon Dioxide - SiO2)
White Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
Opalite
Synthetic Glass (Simulated Opal)
Lepidolite
K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2
Goethite
Goethite (FeO(OH))
Chrysocolla (on host rock)
Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O (Copper silicate)
Chrysocolla
Chrysocolla - (Cu,Al)2H2Si2O5(OH)4·nH2O
Chrysocolla on Quartz
Chrysocolla (Cu2−xAlx(H2−xSi2O5)(OH)4·nH2O) often associated with Quartz (SiO2)
Chert (Beach Pebble)
Silicon Dioxide (SiO2)