Pyrite
Iron Sulfide (FeS2)
mineral
Category
Sedimentary Rock (Technically A Variety Of Chalcedony)
Browse sedimentary rock (technically a variety of chalcedony) specimens identified by the Rock Identifier community.
Fluorite
Calcium Fluoride (CaF2)
mineral
Aventurine
Quartz (Aventurine variety)
Mineral
Yellow Chalcedony (Agate Pebble)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
mineral
Petrified Wood (Silicified Fossil)
Silicified Wood (SiO2)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Shale with Siltstone layering
Sedimentary Clastic Rock (Mudstone/Shale)
sedimentary
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
mineral
Green Opal
Hydrated Silica (SiO2·nH2O)
mineraloid
Milky Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Red Jasper (Skull Carving)
Jasper (Silicon Dioxide, SiO2 plus Iron Oxide inclusions)
sedimentary
Chert (Lake Superior Agate variant)
Microcrystalline Quartz (SiO2)
sedimentary
Banded Calcite (often commercially sold as 'Mexican Onyx' or 'Honey Onyx')
Calcite (Calcium Carbonate, CaCO3)
sedimentary
River Pebble (Gravel)
Clastic sedimentary rock (likely Siltstone or Mudstone pebble; SiO2 with various impurities)
sedimentary
Quartz Crystal Fragment
Silicon Dioxide (SiO2)
mineral
Petrified Wood
Silicified Wood (SiO2)
mineral
Pyrite
Iron Sulfide (FeS2)
mineral
Quartz (Milky or Cloudy variety)
Silicon Dioxide (SiO2)
mineral
Pyrite
Iron Disulfide (FeS2)
mineral
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
mineral
White Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
mineral
Chalcedony (Agate/Chert)
Silicon Dioxide (SiO₂)
mineral
Quartz (Microcrystalline/Chert)
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Shiva Lingam
Cryptocrystalline Quartz (Jasproid/Chalcedony mix)
sedimentary
Red Jasper
Silicon Dioxide (SiO2) - Opaque Chalcedony
sedimentary
Petrified Wood
Silicified wood (Quartz, Chalcedony, or Opal)
sedimentary
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Shale
Fissile mudstone (rich in clay minerals and quartz)
sedimentary
Sandstone (Ferruginous)
Arenite (primarily SiO2 with iron oxide cement)
sedimentary
Sandstone
Arenite (composed primarily of SiO2)
sedimentary
Pebble (likely a type of sandstone or quartzite pebble)
Clastic Sediment (specifically, a rudite-sized clast). If the pebble is composed of a specific rock type, its scientific name would be that rock type (e.g., 'Quartzite pebble', 'Granite pebble', 'Chert pebble'). Given its appearance, it is likely a metamorphic quartzite pebble or a hard sandstone pebble.
Sedimentary rock
Agate (Chert/Chalcedony)
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Pyrite
Iron Disulfide (FeS2)
mineral
Pyrite
Iron Sulfide (FeS2)
mineral
Serpentine
Antigorite, Lizardite, or Chrysotile (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4
metamorphic
Sandstone (Greywacke)
Sandstone (SiO2 enriched with lithic fragments)
sedimentary
Green Apophyllite and Stilbite on Quartz Cluster
Apophyllite-(K) (KCa4(Si8O20)(F,OH)·8H2O), Stilbite-Ca (NaCa4(Si27Al9)O72·28H2O), Quartz (SiO2)
Mineral
Brown Sandstone
Arenite (primarily Quartz and Feldspar, with Iron Oxide cement)
sedimentary
Satin Spar Selenite
Gypsum (CaSO4·2H2O)
mineral