Gneiss
Gneissic Metamorphic Rock
Category
Browse sedimentary (secondary mineral) within igneous specimens identified by the Rock Identifier community.
Gneiss
Gneissic Metamorphic Rock
Limonite (Yellow Ochre)
Hydrated iron(III) oxide-hydroxide (FeO(OH)·nH2O)
Gneiss Pebble
Gneiss (Metamorphic Foliated Rock)
Gneiss
Gneiss
Limonite (Iron Ore)
Limonite (Hydrated Iron Oxide, FeO(OH)·nH2O)
Beach Agate / Quartz Pebble
Silicon Dioxide (SiO2)
Agate
Agate (Silicon Dioxide, SiO2)
Agate
Silicon Dioxide (SiO2) - variety Chalcedony
Carnelian
Carnelian (Cryptocrystalline Quartz, SiO2)
Rhodolite Garnet
Mg3Al2(SiO4)3 - Fe3Al2(SiO4)3 (Pyrope-Almandine series)
Black Spinel
Magnesium Aluminum Oxide (MgAl2O4)
Quartz Pebble
Silicon Dioxide (SiO2)
Pyrite
Iron Sulfide (FeS2)
Coarse-grained Quartz with Feldspar inclusions
Crystalline Quartz (SiO2) with Orthoclase/Plagioclase Feldspar inclusions
Red Jasper
Silicon Dioxide with Hematite (SiO2 + Fe2O3)
Lepidolite
Lepidolite [K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2]
Basalt with Quartz Infill
Basalt (Mafic Extrusive Volcanic Rock)
Brecciated Jasper
Microcrystalline Quartz (SiO2)
Vesicular Basalt
Extrusive mafic igneous rock
Greenstone / Diabase Porphyry
Porphyritic Diabase (Micro-gabbro)
Sandstone (River Rock)
Arenite (composed primarily of SiO2)
Smoky Quartz
Silicon Dioxide (SiO2)
Gold
Native Gold (Au)
Gneiss (Metamorphic Rock Pebble)
Foliated Metamorphic Rock (Quartz-Feldspar Gneiss / Granitic Gneiss)
Shale with Quartz Veins
Fissile Sedimentary Rock (SiO2)
Greenstone (Amygdaloidal Basalt)
Amygdaloidal Basalt (frequently composed of Plagioclase Feldspar, Pyroxene, and Olivine with Chlorite inclusions)
Limestone (with Calcite Veining)
Calcium Carbonate (CaCO3)
Vuggy Limestone
Calcium Carbonate (CaCO3) with Quartz/Calcite inclusions
Travertine (likely polished limestone)
Calcite-rich carbonate rock; predominantly CaCO₃
Limonitic Sandstone with Inclusion
Limonitic Quartz Sandstone (primarily SiO2 with FeO(OH)·nH2O)
Gneiss
Gneiss
River Quartz Pitting/Cobble
Silicon Dioxide (SiO2)
Ruby
Corundum (Al2O3 with Chromium)
White Quartz (Milky Quartz)
Quartz (Silicon Dioxide, SiO2)
Turquoise
CuAl6(PO4)4(OH)8·4H2O (Hydrous phosphate of copper and aluminium)
Yellow Jasper
Silicon Dioxide (SiO2)
Amygdaloidal Basalt with Epidote
Amygdaloidal Basalt (Ca2(Al,Fe)3(SiO4)3(OH))
Chert (Flint / Jasper)
Silicon Dioxide (SiO2)
Limonite (Iron Ore)
FeO(OH)·nH2O (Hydrated Iron Oxide)
Sandstone with Liesegang Rings
Arenite with Iron Oxide Concretions
Gneiss (High-grade Metamorphic Rock)
Gneiss (Metamorphic silicate rock)
Amethyst
Silicon dioxide (SiO2) with iron impurities