Gneiss (Granitic Gneiss)
Gneiss
Category
Browse sedimentary (secondary mineral) within igneous specimens identified by the Rock Identifier community.
Gneiss (Granitic Gneiss)
Gneiss
Quartz crystal with Pyrite inclusions
Silicon Dioxide (SiO2) with Iron Sulfide (FeS2)
Clear Quartz
Silicon Dioxide (SiO2)
Quartz with Limonite Staining
Silicon Dioxide (SiO2) with Hydrated Iron Oxide (FeO(OH)·nH2O)
Peach Moonstone (Orange/Peach Feldspar)
Potassium aluminum silicate (KAlSi3O8)
Quartz Druzy Geode Fragment
Silicon Dioxide (SiO2)
Epidote
Epidote Group (Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH))
Amethyst Quartz
Amethyst (Silicon Dioxide, SiO2)
Pyrite
Iron Sulfide (FeS2)
Aquamarine
Beryl (Be3Al2Si6O18)
Pink Opal / Peruvian Opal
Hydrated amorphous silicon dioxide (SiO2·nH2O)
Celestine (or Celestite) Geode
Strontium Sulfate (SrSO4)
Amethyst Geode
Silicon Dioxide (SiO2) with iron impurities
Dendritic Agate / Moss Agate
Silicon Dioxide (SiO2) with Manganese/Iron oxide inclusions
Agate
Chalcedony (Silicon Dioxide, SiO2)
Peridot
Olivine (Magnesium Iron Silicate - (Mg, Fe)2SiO4)
Green Fluorite
Fluorite (Calcium Fluoride) - CaF2
Basalt
Basalt
Prehnite
Prehnite, Ca2Al2Si3O10(OH)2
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Magnetite
Magnetite (Iron(II,III) oxide, Fe3O4)
Yellow Quartz (Citrine Quartz Pebble)
Silicon Dioxide (SiO2)
Druzy Quartz Geode (Vug)
Silicon Dioxide (SiO2)
Biotite Schist (likely)
Biotite Schist (rock), Biotite (mineral)
Quartz (Iron-stained)
Silicon Dioxide (SiO2) with Hematite/Limonite impurities
Sandstone (Ferruginous)
Arenite (Siliclastic Sedimentary Rock)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Amethyst
Quartz (SiO2) variety
Pyrite
Iron Sulfide (FeS2)
White Quartz Pebble (with possible Quartz Geode cavity)
Silicon Dioxide (SiO2)
Sandstone Cobble with Liesegang Rings
Arenite with iron oxide precipitation (SiO2 matrix with Fe2O3 banding)
Sandstone (with Iron Staining)
Clastic sedimentary rock (SiO2 with Fe2O3 oxides)
Labradorite
(Ca, Na)(Al, Si)4O8 (Plagioclase Feldspar)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Ferruginous Quartz
Quartz (Silicon Dioxide, SiO2) with Iron Oxides
Chert Nodule
Microcrystalline Silica (SiO2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Pink Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
Quartz Pebble (with Mica or Iron staining)
Silicon Dioxide (SiO2)
Gneiss
Gneiss (High-grade metamorphic rock)
Basalt Pebble with Quartz Veining
Basalt (extrusive volcanic rock)