Mineral Within Sedimentary Rock

Quartz (Milky/Smoky variety on matrix)

Silicon Dioxide (SiO2)

Chert (specifically Agate/Jasper variety)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Gneiss

Gneiss (High-grade regional metamorphic rock)

Chert (Tan/Yellow variety)

Microcrystalline quartz (SiO2)

Chert (and/or Flint)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Sandstone (Quartzose)

Arenite (composed primarily of SiO2)

Quartz Vein in Host Rock

Silicon Dioxide (SiO2) within Sedimentary/Metamorphic Matrix

Chalcedony (Botryoidal/Agate nodule)

Microcrystalline Quartz (SiO2)

Turquoise

Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]

Quartz Geode

Silicon Dioxide (SiO2)

Chert (varietal: Flint/Jasper mix)

Hydrous Silica (SiO2)

Mica Schist

Mica Schist (predominantly Muscovite or Biotite sheet silicates)

Chert (Septarian Concretion/Nodule)

Microcrystalline silica (SiO2) with carbonate mineral veining

Limestone with Algal/Lichen Colonization

Calcium Carbonate (CaCO3)

Quartz (Drusy/Crystalline variety)

Silicon Dioxide (SiO2)

Carnelian

Carnelian (Silicon Dioxide - SiO2)

Conglomerate (Puddingstone)

Conglomerate (specifically, clastic sedimentary rock)

Ironstone (with possible Hematite/Limonite coating)

Ironstone (Fe-rich sedimentary rock)

Jasper with Hematite inclusions

Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3)

Turquoise

Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]

Sandstone (likely Arkosic or Quartzose)

Sandstone (SiO2 with inclusions)

Chert Pebble with Quartz Veins

Microcrystalline Quartz (SiO2)

Gneiss

Gneissic Metamorphic Rock

Turquoise

Hydrated phosphate of copper and aluminium: CuAl6(PO4)4(OH)8·4H2O

River Rock

Sedimentary Rock (various compositions)

Shale or Slaty Mudstone

Argillaceous sedimentary rock

Dalmatian Stone

Peralkaline Quartz-Feldspar Porphyry with Arfvedsonite

Milky Quartz

Silicon Dioxide (SiO2)

Dalmatian Stone

Dalmatian Jasper (Aplitic Rock)

Gneiss

Gneiss

Yellow Chalcedony (common opal or chert variant)

Silicon Dioxide (SiO2)

Sandstone (Ferruginous)

Arenite (composed primarily of SiO2 with Fe2O3 staining)

Chert (Nodule)

Silicon Dioxide (SiO2)

Amethyst

Amethyst (Silicon Dioxide - SiO2 with iron impurities)

Quartz Druze on Matrix (Geode Fragment)

Quartz (Silicon Dioxide, SiO2)

River Chalcedony / Agate

Chalcedony (Silicon Dioxide, SiO2)

Jasper (likely Ocean Jasper or Variegated Jasper)

Silicon Dioxide (SiO2) with impurities

Ironstone Concretion / Limonite-stained Siltstone

Ironstone (primarily Limonite FeO(OH)·nH2O and Siltstone)

Chert (Agatized)

Silicon dioxide (SiO2)

Devil's Toenail

Gryphaea (extinct genus of foam oysters, typically composed of Calcite CaCO3)

Pyrite Geode (Sparkling Druzy)

Iron Sulfide (FeS2) in Sedimentary Nodule

Sandstone

Arenite (SiO2 primarily)