Chert (often called Flint)
Microcrystalline Quartz (SiO2)
Category
Browse sedimentary rock (specifically a clastic sedimentary rock formed into a cobble) specimens identified by the Rock Identifier community.
Chert (often called Flint)
Microcrystalline Quartz (SiO2)
Vuggy Quartz on Matrix
Silicon Dioxide (SiO2)
Carnelian
Carnelian (Chalcedony / SiO2)
Druzy Quartz (part of a Geode)
Silicon Dioxide (SiO2)
Fluorite with Quartz coating
Calcium Fluoride (CaF2) with Silicon Dioxide (SiO2)
Quartz Geode
Silicon Dioxide (SiO2)
Jasper
Cryptocrystalline Quartz (SiO2)
Quartz (Milky Quartz / Quartzite)
Silicon Dioxide (SiO2)
African Turquoise
African Turquoise (a trade name for Jasper, a variety of Chalcedony: SiO2)
Quartz Vein in Host Rock (Breccia/Rhyolite)
Silicon Dioxide (SiO2) with matrix
Mookaite Jasper
Silicon Dioxide (SiO2) - Radiolarite
Chert (concretionary/nodular variant)
Microcrystalline Quartz (SiO2) with possible fossil or mineral inclusions
Herkimer Diamond (Quartz Crystal)
Silicon Dioxide (SiO2)
Chert (Nodular)
Microcrystalline Silica (SiO2)
Chert (varietal: Flint/Jasper mix)
Hydrous Silica (SiO2)
Pebble (likely Quartz or Chert)
SiO₂ (Silicon Dioxide) - referring to the likely main mineral composition, Quartz. If it's chert, the scientific name remains SiO₂ with a microcrystalline structure.
Red Jasper
Silicon Dioxide with Iron Oxide inclusions (SiO2 + Fe2O3)
Gneiss
Gneissic Metamorphic Rock
Quartz River Cobble
Silicon Dioxide (SiO2)
Biotite Schist
Biotite Schist
Druzy Quartz Geode (Vug)
Silicon Dioxide (SiO2)
Porphyry
Porphyritic Andesite/Dacite
Basalt River Pebble
Aphanitic Mafic Basalt
Quartz-Veined Mudstone
Argillaceous Mudstone with Quartz Veining
Fossil Sand Dollar (Echinoidea)
Phylum Echinodermata, Class Echinoidea (likely Dendraster or Scutella)
Quartz Geode
Silicon Dioxide (SiO2)
Calcite Geode
Calcium Carbonate (CaCO3)
Gneiss
Gneiss (High-grade metamorphic rock)
Quartzite (specifically Milky Quartz variety)
Quartz (SiO2)
Jasper
Jasper (Silicon Dioxide, SiO2)
Chert (varietal: Flint Pitted Pebble)
Cryptocrystalline Quartz (SiO2)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Fancy Jasper
Silicon Dioxide (SiO₂)
Almandine Garnet
Almandine (Fe3Al2Si3O12)
Dalmatian Stone
Dalmatian Jasper (a misnomer) / Perthitic Igneous Rock
Limonite (Iron Ore)
FeO(OH)·nH2O (Hydrous ferric oxide)
Chert / Flint
Cryptocrystalline Quartz (Silicon Dioxide, SiO2)
Biotite Mica
Biotite (K(Mg,Fe)3AlSi3O10(F,OH)2)
Amethyst (Chevron or Banded variety)
Silicon Dioxide with Iron impurities (SiO2)
Wonderstone
Rhyolite (Silicon Dioxide with Iron Oxide impurities)
Jasper with Quartz inclusions
Silicon Dioxide (SiO2)
Fossilized Shell in Limestone
Bivalve fossil (CaCO3) in Carbonate Sedimentary Rock