Mineral, Often Found As A Rock

Unakite

Epidotized Granite

Limonite and Goethite (Ironstone)

Hydrous Iron Oxide Mixture (FeO(OH)·nH2O)

Chert (Chert / Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Yellow Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Conglomerate

Lithified, poorly sorted gravel; composition is uncertain from the image

Geode

Quartz nodule / Chalcedony-lined cavity

Chert / Flint Nodule

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (varietal: Jasper or Flint)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Milky Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Blue Apatite

Calcium Phosphate (Ca5(PO4)3(F,Cl,OH))

Chert (often called Flint when dark or found in chalk)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Septarian Nodule (Brown)

Septarian Concretion (Calcite, Aragonite, Limestone, and Barite)

Quartzite (Ferruginous)

SiO2 (Metamorphosed Sandstone)

Conglomerate

Clastic sedimentary rock (Conglomerate)

Weathered iron-rich rock, possibly limonite/goethite

Limonite (hydrated iron oxides; commonly goethite, FeO(OH), mixed with hematite)

Almandine Garnet

Almandine (Fe3Al2(SiO4)3)

Chert (variations include Flint/Jasper)

Cryptocrystalline Silicon Dioxide (SiO2)

Quartzite with Quartz Veining

Metamorphic Quartz Rock (SiO2)

Agate

SiO2 (Silicon Dioxide) - Chalcedony

Milky Quartz with Mineral Inclusions

Quartz (Silicon Dioxide, SiO2)

Green Banded Chert (Agate/Jasper)

Silicon Dioxide (SiO2) with trace impurities of Chlorite or Glauconite

Chert (Flint)

Microcrystalline Quartz (SiO2)

Weathered Sedimentary Rock

Sedimentary Rock

Chert (Flint)

Microcrystalline Quartz (SiO2)

Milky Quartz with Chlorite Schist Inclusions

Quartz (SiO2) with Chlorite Group silicates (typically (Mg,Fe)3(Si,Al)4O10(OH)2)

Banded Gneiss (River Rock/Pebble)

Gneiss (specifically a banded variety often found as a river rock)

Chert

Chert (Microcrystalline Quartz, SiO2)

Chert (Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chalcedony (Carnelian)

Silicon Dioxide (SiO2)

Jasper

Silicon dioxide (SiO2)

Quartz-veined Metamorphic Rock

Quartz Vein in Phyllite or Schist (SiO2 in Silicate Matrix)

Jasper (likely a variety of Brecciated Jasper or a patterned variety)

Silicon dioxide (SiO2)

Hag Stone

Perforated Sedimentary Rock / Flint / Limestone

Sandstone and Conglomerate pebbles

Sedimentary clastic rock

Chrysocolla on Quartz

Chrysocolla (Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O) with Quartz (SiO2)

Polished bronzite-rich serpentinized rock

Serpentinite or serpentinized peridotite, likely containing bronzite (orthopyroxene) and magnetite

Yooperlite (Sodalite-bearing Syenite)

Sodalite-rich Syenite (Na8(Al6Si6O24)Cl2)

Granite (specifically Rapakivi Granite)

Phaneritic Felsic Igneous Rock (Granite)

Magnetite

Magnetite (Fe3O4)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Chert (Grey-Green Flint)

Microcrystalline silicon dioxide (SiO2)