Quartz-encrusted Matrix
Silicon Dioxide (SiO2) with Ferruginous Sandstone
Category
Browse sedimentary or mineral specimens identified by the Rock Identifier community.
Quartz-encrusted Matrix
Silicon Dioxide (SiO2) with Ferruginous Sandstone
Biotite Schist
Biotite Gneiss/Schist (approximate formula K(Mg,Fe)3AlSi3O10(OH)2)
Pyrite
Iron Pyrite (FeS2)
Howlite
Ca2B5SiO9(OH)5
Chalcedony (Yellow Chert / Agate)
Quartz (Silicon Dioxide - SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Brown Chalcedony (Agate/Jasper)
Cryptocrystalline Quartz (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Blue Kyanite
Kyanite (Al2SiO5)
Howlite
Calcium borosilicate hydroxide (Ca2B5SiO9(OH)5)
Jasper
Silicon Dioxide (SiO2)
Kyanite
Kyanite (Al2SiO5)
Pyrite
Iron Sulfide (FeS2)
Carnelian
Carnelian (SiO2)
Pyrite and Sunstone
Iron Sulfide (FeS2) and Plagioclase Feldspar ((Ca,Na)Al(Al,Si)Si2O8)
Garnet
Garnet (X3Y2(SiO4)3)
Chalcedony (Agate/Carnelian type)
Silicon Dioxide (SiO2)
Gneiss
Gneiss (High-grade metamorphic rock)
Banded Gneiss
Gneiss (Metamorphic Rock)
Unopened Geode
Geode (containing various mineralization like Quartz SiO2)
Sandstone (Ferruginous)
Ferruginous Sandstone (SiO2 with Fe2O3)
Sandstone
Arenite (primarily SiO2)
Asphalt Chunk (Bituminous Concrete)
Aggregated Bitumen / Artificial Breccia
Dendritic Agate
Silicon Dioxide with Manganese or Iron Oxide inclusions (SiO2)
Red Sandstone Pebble
Arenite (primarily Quartz SiO2 with Hematite Fe2O3 staining)
Sandstone (Quartzose)
Arenite (primarily SiO2)
Sandstone (Pebble)
Arenite (SiO2 based)
Opal
Hydrated silica (SiO2·nH2O)
Herkimer Diamond (Quartz)
Silicon Dioxide (SiO2)
Sandstone (lithic/greywacke variant)
Clastic sedimentary rock (primarily SiO2 with rock fragments)
Green Aventurine
Silicon dioxide (SiO2) with fuchsite inclusions
Amethyst (Geode/Druzy)
Silicon Dioxide (SiO2) with iron impurities
Shale with Iron Oxide Staining
Fissile Mudstone (primarily clay minerals and quartz)
Pyrite
Iron Sulfide (FeS2)
Quartz (likely Herkimer Diamond style)
Silicon Dioxide (SiO2)
Sandstone (with Iron Staining)
Clastic sedimentary rock (primarily Quartz with Limonite/Goethite staining)
Sandstone (likely Quartzose Sandstone)
Arenite (primarily SiO2)
Sandstone
Arenite (SiO2 based)
Fossilized Sea Urchin (Echinoid)
Echinoidea (Class) - likely replaced by Calcite or Quartz
Sandstone (Ferruginous)
Arenite (primarily SiO2 with Fe2O3 cementation)
Red Sandstone
Sandstone (Quartz Arenite / Arkose with Hematite cement)