Mineral Within A Sedimentary Rock

Ironstone Concretion / Goethite Nodules

Ironstone (composed primarily of Goethite FeO(OH) and Limonite)

Quartz Geode

Silicon Dioxide (SiO2) in a Secondary Sedimentary/Volcanic cavity

Chert / Flint

Chert (Silicon Dioxide, SiO2)

Gneiss (specifically Micaceous Gneiss)

Gneiss (High-grade Regional Metamorphic Rock)

Conglomerate with Quartz Inclusions

Conglomerate (clastic sedimentary rock) with internal Quartz (SiO2)

Slate

Slate (Foliated Metamorphic Rock)

Chert (Nodule)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Limonite-stained Chert

Silicon Dioxide (SiO2) with Hydrated Iron Oxide (FeO(OH)·nH2O)

Jasper Chert Nodules

Silicon Dioxide (SiO2) with Hematite impurities

Septarian Nodule (Galt)

Calcareous concretion / Septarian concretion

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Ironstone Concretion (Moqui Marble)

Iron Oxide Concretion (Fe2O3 / FeO(OH) mixed with SiO2)

Green Aventurine

Quartzite with Fuchsite inclusions (SiO2 + K(Al,Cr)2(AlSi3O10)(OH)2)

Mica Schist

Mica Schist (Composition typically contains Muscovite: KAl2(AlSi3O10)(OH)2 or Biotite: K(Mg,Fe)3AlSi3O10(OH)2 along with Quartz and Feldspar)

Chalcedony in Matrix

Silicon Dioxide (SiO2)

Turquoise

Hydrated phosphate of copper and aluminum; CuAl6(PO4)4(OH)8·4H2O

Chert / River Jasper

Microcrystalline Quartz (SiO2)

Vesicular Sandstone

Clastic Sedimentary Rock (Sandstone)

Quartz-veined Siltstone/Greywacke

Clastic Sedimentary Rock with Quartz Infill (SiO2 vein)

Gneiss

Gneiss

River Stone / Pebble

Clastic Sediment (composed largely of Quartz, Feldspar, and various rock fragments)

Ironstone (Limonitic Concretion)

Limonite (FeO(OH)·nH2O) with Goethite and Hematite inclusions

Quartz Druse (on Chalcedony/Agate base)

Silicon Dioxide (SiO2)

Shale with Plant Fossils / Carbonaceous Shale

Laminated Mudrock (Siliciclastic)

Chert / Flint

Chert (Microcrystalline Quartz, SiO2)

Garnet Schist

Almandine Garnet-Mica Schist (X₃Y₂(SiO₄)₃)

Smoky Quartz and Biotite Schist

Quartz-Biotite Schist (SiO2 + K(Mg,Fe)3AlSi3O10(F,OH)2)

Red Jasper

Jasper (Silicon Dioxide, SiO2)

Chert (Jasper/Flint variety)

Silicon Dioxide (SiO2)

Chert (Nodule)

Chert (composition: SiO2)

Banded Calcite (often sold as 'Travertine' or 'Mexican Onyx')

Calcium Carbonate (CaCO3)

Fluorite in Matrix

Fluorite (CaF2) within a host rock matrix

Ferruginous Chert (Jasper)

Silicon Dioxide (SiO2) with iron oxide inclusions

Yellow Jasper (within host rock)

Silicon Dioxide (SiO2) with iron hydroxides (Goethite)

Chert (Jasper variety)

Silicon Dioxide (SiO2)

Garnet-Bearing Gneiss

Almandine-Garnet Gneiss

Banded Rock (likely Quartz-rich)

Uncertain, likely a Metamorphic Rock (e.g., Gneiss or Schist) with prominent Quartz and other minerals

Gneiss (with Quartz-Feldspar vein)

Gneiss (high-grade metamorphic rock) containing Quartz (SiO2) and Feldspar (KAlSi3O8 – NaAlSi3O8 – CaAl2Si2O8)

Chert (Flint)

Microcrystalline Quartz (SiO2)

Mica Schist

Mica Schist (KAl2(AlSi3O10)(OH)2 / K(Mg,Fe)3AlSi3O10(OH)2)

Chert (often called Flint when dark)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Precious Opal in Matrix

Hydrated Silica (SiO2·nH2O)