Petrified Wood
Silicified wood (SiO2)
Category
Browse sedimentary (with some aspects of mineral replacement) specimens identified by the Rock Identifier community.
Petrified Wood
Silicified wood (SiO2)
Pink Gneiss / Pink Granite Gneiss
Felsic Gneiss (dominated by Orthoclase Feldspar and Quartz)
Quartz Geode
Silicon Dioxide (SiO2)
Red Jasper
Silicon Dioxide (SiO2) with Hematite impurities
Porphyritic basalt (likely amygdaloidal basalt)
Basalt, a mafic volcanic rock; composition typically plagioclase + pyroxene, with possible olivine and vesicle-filling minerals
Sandstone
Quartz Sandstone (predominantly)
Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
Garnet Gneiss
Gneiss containing Almandine Garnet
Gneiss
Gneissic Metamorphic Rock
Flint nodule
Sedimentary cryptocrystalline quartz (SiO2)
Polished hematite bead necklace
Hematite (iron(III) oxide, Fe₂O₃), likely polished beads
Banded Gneiss (with Quartz Vein)
Gneiss (Metamorphic rock of varying mineralogy)
Red Jasper
Silicon dioxide (SiO2) with iron oxide (Fe2O3) inclusions
Gneiss (or Granite Gneiss)
Metamorphic rock rich in quartz, feldspar, and biotite/amphibole
Celestite Geode
Strontium Sulfate (SrSO4)
Lepidodendron Fossil (Scale Tree)
Lepidodendron sp.
Magnetite
Magnetite (Fe3O4)
Chert
Siliceous sedimentary rock (predominantly microcrystalline quartz, SiO2)
Gneiss
Gneiss
Petrified Wood
Silicified wood (Quartz/Chalcedony replacement of cellulose)
Fossilized Sea Urchin (Echinoid)
Echinoidea (Fossil specimen, often replaced by Calcite or Silica)
Chalcedony (Agate/Seashell replacement)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
Rainbow Fluorite
Fluorite (Calcium Fluoride, CaF2)
Chert (Flint / Chalcedony pebble)
Silicon Dioxide (SiO2)
Chert (Jasper/Agate mix)
Microcrystalline Quartz (SiO2)
Chert Nodules / Flint
Chert (Silicon Dioxide, SiO2)
Chert (Yellow Jasper/Flint)
Silicon Dioxide (SiO2)
Red Jasper
Jasper (Silicon Dioxide, SiO2 with iron oxide impurities)
Chert (often called Flint or Jasper)
Silicon Dioxide (SiO2)
Gneiss
Metamorphic Gneiss (High-grade regional metamorphism)
Petrified Wood
Silicified wood (Quartz variant, SiO2)
Banded Gneiss Pebble
Banded Gneiss
Flint
SiO2 (Cryptocrystalline Quartz / Chert)
Quartz (Chert/Flint variety)
Silicon Dioxide (SiO2)
Chert / Flint Pebble
Microcrystalline quartz (SiO2)
Chert / Flint
Silicon Dioxide (Microcrystalline Quartz, $SiO_2$)
Flint / Chert (Beach-worn Pebble)
Microcrystalline quartz (SiO2)
Flint / Chert
Cryptocrystalline quartz (SiO2)
Black Chert River Stone
Cryptocrystalline Quartz (SiO2)
Chert (Chalcedony)
Silicon Dioxide (SiO2)
Chert (Flint Nodules)
Silicon Dioxide (SiO2)
Garnet-Bearing Gneiss
Garnetiferous Feldspathic Gneiss