Sedimentary (Man Made Conglomerate)

Turquoise

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

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Sandstone

Arenite (SiO2 based)

Hematite

Iron(III) oxide (Fe2O3)

Sandstone

Arenite (primarily SiO2 with trace Fe2O3)

Limestone

Calcium Carbonate (CaCO3)

Chert / Red Jasper

Microcrystalline Quartz (SiO2)

Glauconite

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

Chert (Jasper variety)

Microcrystalline Quartz (SiO2)

Limonite Sandstone

Ferruginous Sandstone (Hydrated Iron Oxide)

Yellow Chalcedony (Agate)

Silicon Dioxide (SiO2)

Yellow Calcite

Calcium Carbonate (CaCO3)

Blue Chalcedony

Silicon Dioxide (SiO2)

Chert (Nodule)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Quartz Geode

Silicon Dioxide (SiO2)

Howlite

Calcium borosilicate hydroxide (Ca2B5SiO9(OH)5)

Satin Spar (often sold as Selenite)

Gypsum (CaSO4·2H2O)

Blue Celestite (Celestine)

Strontium sulfate (SrSO4)

Quartz Crystal Fragment

Silicon Dioxide (SiO2)

Satin Spar (Gypsum)

Hydrous Calcium Sulfate (CaSO4·2H2O)

Garnet (specifically Almandine)

Almandine - Fe3Al2(SiO4)3

Note: Image shows a biological specimen (Rat), not a rock. Representative geological equivalent: Galena (due to lead-grey colors in fur).

Galena (PbS)

Zoisite with Ruby

Anyolite (Calcium aluminum hydroxy silicate with Corundum) Ca2Al3(SiO4)3(OH)

Limonite (Iron Ore)

FeO(OH)·nH2O (Hydrated iron(III) oxide-hydroxide mixture)

Hag Stone

Perforated Sedimentary Rock (typically Limestone or Sandstone)

Chert (specifically Flint)

Microcrystalline quartz (SiO2)

Quartz

Silicon Dioxide (SiO2)

Chert (Commonly known as Flint or River Pebble)

Microcrystalline Quartz (SiO2)

Jasper Agate (specifically Brecciated Jasper)

Silicon Dioxide (SiO2) with iron oxide and clay impurities

Ammonite Fossil

Ammonoidea (primarily composed of Calcite, CaCO3)

Jasper Chert Nodules

Silicon Dioxide (SiO2) with Hematite impurities

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Crinoid Fossil in Limestone

Crinoid (Class Crinoidea) in Fossiliferous Limestone (CaCO3)

Sandstone (Quartz Arenite)

Clastic Sedimentary Rock - Quartz Arenite

Sandstone (Graywacke type)

Clastic Sedimentary Rock (Lithic Sandstone)

Picture Jasper

Silicon Dioxide (SiO2) with iron oxide and organic impurities

Chert (Flint Nodules)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Flint Nodules)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (specifically Flint or Jasper variant)

Silicon Dioxide (SiO2)

Chert (or Chalcedony)

Chert (Microcrystalline Quartz, SiO2)

Banded Chert

Microcrystalline Quartz (SiO2)

Chert (Flint)

Chert (Silicon Dioxide, SiO2)