Sedimentary (With Some Aspects Of Mineral Replacement)

Banded Gneiss

Gneiss (High-grade Metamorphic Rock)

Pyrite (Fool's Gold)

Iron Disulfide (FeS2)

Banded Flint (Polished Stripe Flint)

Silicon Dioxide (SiO2) - variety of Chert

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Jasper Agate

Silicon dioxide (SiO2)

Conglomerate

Conglomerate (Detrital sedimentary rock)

Yellow Jasper

Silicon Dioxide (SiO₂)

Chert (Flint variety)

Microcrystalline Silica (SiO2)

Jasper (Red/Brown Variety)

Jasper (Microcrystalline Quartz, SiO2)

Chert (variously Flint or Jasper gravel)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Chert (Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (White Chert/Flint)

Chert (SiO2)

Gneiss (with Quartz and Biotite Mica)

Gneiss

Shale (Ferruginous)

Laminated Mudrock (Siliciclastic Sedimentary Rock)

Banded Gneiss

Gneiss (Metamorphic high-grade, predominantly SiO2, Al2O3, K2O, Na2O)

Petoskey Stone (Petrified Favosites)

Favosites (extinct colonial coral), CaCO3 with Silica replacement

Jasper with Iron Staining

Silicon Dioxide (SiO2) with impurities

Stromatolite

Laminated biogenic sedimentary structure (formed by Cyanobacteria)

Green Jasper (with Quartz veining)

Jasper (Silica-rich microcrystalline variety of Quartz), formula: SiO2

Gneiss (specifically a weathered Amphibolite or Garnet Gneiss)

Gneiss (complex silicate composition)

Gossan with Copper Carbonate (Chrysocolla/Malachite)

Ferruginous Oxide (Gossan) with Cu2CO3(OH)2 (Malachite) or (Cu,Al)2H2Si2O5(OH)4 (Chrysocolla)

Conglomerate (Red Sandstone variety)

Clastic Sedimentary Rock (Conglomeratic Sandstone)

Shale

Fissile Mudstone (primarily composed of clay minerals and quartz grains)

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2)

Chert

Chert (microcrystalline quartz)

Quartz Geode

Silicon Dioxide (SiO2)

Banded Sandstone

Arenite with Liesegang banding

Sandstone with Iron Oxide (Limonite/Hematite)

Ferruginous Sandstone (SiO2 with FeO(OH)·nH2O)

Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

Chert (Arrowhead Fragment)

Chert / Microcrystalline Silicon Dioxide (SiO2)

Chert (Iron-stained)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Fancy Jasper (Agate/Chert mix)

Silicon Dioxide (SiO2) with impurities

Jasper (specifically a banded or dark variety)

Silicon Dioxide (SiO2) with impurities

Chert (Jasper/Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (often called Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (variations include Flint/Novaculite)

Chert (formula: SiO2)

Chert (specifically Flint or Gray Chalcedony)

Microcrystalline Quartz (SiO2)

Chert Nodule (with Ironstone Cortex)

Microcrystalline Silica (SiO2)

Chert (varietal: Flint or River Pebble)

Silicon Dioxide (SiO₂)

Chert (Jasper variety)

Silicon Dioxide (SiO2)

Chert (often called Flint or River Rock)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Quartz Variety)

Chert (Silicon Dioxide, SiO2)