Gneiss
Gneiss
Category
Browse sedimentary (with some aspects of mineral replacement) specimens identified by the Rock Identifier community.
Gneiss
Gneiss
Petrified Wood
Silicon Dioxide (SiO2) - Calcified / Silicified Wood
Gneiss
Gneiss
Gneiss
Gneiss
Chert
Chert (Microcrystalline Quartz, SiO2)
Quartz Geode Fragment
Silicon Dioxide (SiO2)
Orange Calcite
Calcium Carbonate (CaCO3)
Quartz (Milky or Cloudy Quartz)
Silicon Dioxide (SiO2)
Chert (Commonly known as Flint)
Microcrystalline Quartz (SiO2)
Sandstone (Ferruginous)
Arenite (SiO2 with Fe-oxide cement)
Gneiss
Gneiss (Metamorphic Rock)
Fossil Coral
Hexagonaria / Rugosa / Scleractinia
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Chert (Agatized/Chalcedony variety)
Microcrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Chalcedony (specifically Agate or Water-worn Quartzite)
Silicon Dioxide (SiO2)
Banded Gneiss
Gneiss (Metamorphic high-grade rock)
Celestite (Celestine)
Strontium sulfate (SrSO4)
Dalmatian Stone
Peralkaline rhyolite with arfvedsonite (formerly incorrectly called Dalmatian Jasper)
Fossil Crab
Decapoda (likely Avitelmessus or Raninidae family)
Quartz pebble
Silicon dioxide (SiO2)
Gneiss
Gneiss
Sandstone Beach Pebble
Clastic sedimentary rock (SiO2 with iron oxide cement)
Petrified Wood
Silicified Wood (SiO2)
Concretion
Calcareous or ferruginous concretion
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Gneiss
Gneiss (High-grade metamorphic rock)
Ironstone Concretion
Siderite or Hematite Concretion
Fossil Coral
Rugosa or Tabulata coral fossil
Flint (or Chert)
Silicon dioxide (SiO2) microcrystalline quartz
Flint
SiO2 (Microcrystalline Quartz / Chert)
Flint (or Chert)
Silicon dioxide (Microcrystalline Quartz, $SiO_2$)
Flint / Chert
Microcrystalline Quartz (SiO2)
Chert / Flint
Silicon dioxide (SiO2)
Flint
SiO2 (Microcrystalline Quartz / Chert)
Yellow Chert Pebbles/Yellow Jasper
Microcrystalline Quartz (SiO2) with Goethite or Limonite inclusions
Chert
Chert (Microcrystalline Quartz, SiO2)
Chert (Nodule)
Silicon Dioxide (SiO2)
Chert (Green Chert or Jasper)
Silicon Dioxide (SiO2)
Blue Celestite (with Galena)
Strontium sulfate (SrSO4) and Lead sulfide (PbS)
Petrified Wood
Silicified Wood (SiO2)
Magnetite Orthorthotropic Rock
Magnetite (Fe3O4)