Sedimentary Rock (Altered)

Glauconitic Sandstone (Greensand)

Glauconitic Sandstone ((K, Na)(Fe3+, Al, Mg)2(Si, Al)4O10(OH)2)

Chert Pebble with Quartz Veining

Microcrystalline Quartz (SiO2)

Garnet Schist

Almandine-Garnet Mica Schist

Red Sandstone

Arenite (Fe2O3 rich)

Halite (Rock Salt)

Halite (Sodium Chloride, NaCl)

Carnelian

Carnelian (SiO2, Silicon Dioxide with Iron Oxide impurities)

Quartz (likely) / Siliceous rock with quartz phenocrysts (if a rock fragment)

Quartz (SiO₂)

Sandstone Concretion

Arenaceous concretion (primarily SiO2 with Fe2O3 staining)

Stromatolite

Laminated biogenic sedimentary structure (formed by Cyanobacteria)

Jasper (Green Jasper / Chert)

Silicon Dioxide (SiO2) with iron/clay inclusions

Chalcedony in Host Rock

Chalcedony (SiO2)

Iron-stained Quartzite / Chert

Silicon Dioxide (SiO2) with Hematite/Limonite impurities

Red Jasper

Silicon dioxide (SiO2) with iron oxide inclusions

Red Jasper (Heliotrope family variant)

Silicon Dioxide with Hematite inclusions (SiO2 + Fe2O3)

Tufa

Calcareous Tufa (CaCO3)

Sodalite

Sodalite (Na8(Al6Si6O24)Cl2)

Chert (Nodule)

Silicon dioxide (SiO2) - Cryptocrystalline Quartz

Chert / Flint Nodule

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Jasper

Jasper (Silica/Quartz) - SiO2

Chert (Nodule)

Silicon Dioxide (SiO2)

Orthoceras Fossil in Limestone

Orthoceras (extinct genus of cephalopods), mineralized as Calcite (CaCO3) in Fossiliferous Limestone

Gneiss

High-grade regional metamorphic rock (Foliated)

Marble (Carrara style)

Recrystallized Calcite-rich Metamorphic Rock (CaCO3)

Marble

Recrystallized Calcite Rock (CaCO3)

Red Jasper

Silicon Dioxide (SiO2) with Hematite inclusions

Quartz (Milky/Crystal Variety)

Silicon Dioxide (SiO2)

Sandstone

Arenite (composed primarily of SiO2)

Banded Gneiss

Gneiss (High-grade regional metamorphic rock)

Chert (varieties include Flint or Jasper)

Chert (cryptocrystalline quartz; SiO₂)

Green Moss Agate

Silicon Dioxide (SiO2) with inclusions of hornblende or chlorite

Yellow Calcite

Calcium Carbonate (CaCO3)

Banded Sandstone (Zebra Stone)

Arenite with Iron Oxide Banding (Liesegang rings)

Quartz (Clear Quartz/Rock Crystal)

Silicon Dioxide (SiO2)

Granite Gneiss

Gneiss (High-grade Metamorphic Rock)

Gneiss (Metamorphic Rock)

Gneiss (high-grade regional metamorphic rock)

River Stone (River Pebbles)

Alluvial Deposit (typically Quartzite, Sandstone, or Granite clasts)

Chert (Jasper/Agate variety)

Microcrystalline Quartz (SiO2)

Graywacke

Graywacke (immature sandstone)

Chert (Quartz Variety)

Chert (Silicon Dioxide, SiO2)

Chert (Quartzite-rich River Pebble)

Silicon Dioxide (SiO2)

Chert (Jasper variety)

Silicon Dioxide (SiO2)

Fossilized Coral

Scleractinia (fossil order), primarily Calcium Carbonate (CaCO3)