Flower Agate
Chalcedony (cryptocrystalline Quartz) with Spherulite inclusions; SiO2
Category
Browse sedimentary rock (technically a variety of chalcedony) specimens identified by the Rock Identifier community.
Flower Agate
Chalcedony (cryptocrystalline Quartz) with Spherulite inclusions; SiO2
Chert (Jasper/Agate variety)
Microcrystalline Quartz (SiO2)
Chert (Flint variety)
Chert (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Blue Lace Agate
Chalcedony (SiO2) with trace minerals
Rough Garnet in Matrix
Almandine Garnet (Fe3Al2Si3O12)
Chert (Jasper/River Pebble)
Silicon Dioxide (SiO2)
Red Swirl Beads (Likely Resin or Glass, simulating Red Jasper or Agate)
N/A (for the beads as pictured); Red Jasper: SiO2 (Chert variety); Red Agate: SiO2 (Chalcedony variety)
Shale
Fissile Mudstone (primarily composed of phyllosilicate minerals like kaolinite, montmorillonite, and illite)
Chert (Flint)
Chert (SiO2)
Quartz
Silicon Dioxide (SiO₂)
Amazonite
KAlSi3O8 (Potassium Feldspar, variety of Microcline)
Sandstone (likely Arkose or Quartz Sandstone)
Arenite (SiO2 principal component)
Sandstone (Muddy/Silty Variety)
Arenite with high silt/clay content (clastic sedimentary rock)
Limestone Pebble
Calcium Carbonate (CaCO3)
Chert (or Flint)
Silicon dioxide (SiO2)
Porphyritic Basalt (Chinese Flower Stone / Chrysanthemum Stone basalt variety)
Porphyritic Basalt containing Plagioclase Feldspar phenocrysts
Chert (Jasper)
Chert / Microcrystalline Quartz (SiO2)
Chert (Arrowhead variety)
Chert (SiO2)
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
Chert (Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Jasper/Agate variety)
Silicon Dioxide (SiO2)
Chert / Jasper
Microcrystalline Quartz (SiO2)
Limonite (Iron Stone)
Limonite (Hydrated Iron Oxide) - FeO(OH)·nH2O
Almandine Garnet in Schist
Almandine, Fe3Al2(SiO4)3
Chert (Chert Nodule with Cortex)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Yellow Chalcedony (Agate)
Silicon Dioxide (SiO2)
Ironstone Concretion (Moqui Marble variety)
Ferruginous Sandstone Concretion
Chert (specifically Flint or Dark Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Red Jasper
Silicon dioxide (SiO2) with iron inclusions
Limestone
Calcium Carbonate (CaCO3)
Labradorite (a variety of Feldspar)
Labradorite; (Na,Ca)(Al,Si)4O8 (a plagioclase feldspar)
Limestone
Calcium Carbonate (CaCO3)
Tiger's Eye
SiO2 (Quartz with inclusion of iron oxides)
Quartz (likely) / Siliceous rock with quartz phenocrysts (if a rock fragment)
Quartz (SiO₂)
Agate Geode
Microcrystalline Quartz (SiO2)
Ocean Jasper
Spherulitic Chalcedony (SiO2)
Fossilized Turritella Gastropod (Internal Mold)
Turritella (Fossil Gastropod Crust)
Chert
Siliceous sedimentary rock (predominantly microcrystalline quartz, SiO2)
Thunderegg (specifically a Jasper/Agate-filled Geode nodule)
Silicon Dioxide (SiO2) within Rhyolitic Matrix
Specular Hematite
Hematite (Fe2O3)
Chert (Common Opal/Chalcedony mixture)
Silicon Dioxide (SiO2)