Man Made Rock (Sedimentary Analogue)

Garnet Schist

Almandine-mica schist

Druzy Chalcedony (Agate Geode)

Silica (SiO2) - Cryptocrystalline Quartz with druzy macrocrystalline quartz

River Pebble (Gneiss or Quartzite mixture)

Metamorphic rock (Commonly Gneissic)

Banded Gneiss

Gneiss (Metamorphic Rock)

Petoskey Stone

Hexagonaria percarinata (Fossilized Rugose Coral)

Sandstone

Clastic Sedimentary Rock (composed mostly of SiO2)

Banded Chert

Silicon Dioxide (SiO2)

Sandstone (Quartz-rich Pebble)

Arenite (primarily SiO2)

Red Sandstone

Arenite

Limonite (Iron Ore)

FeO(OH)·nH2O (Hydrated Iron Oxide)

Sandstone (Banded)

Arenite (primarily SiO2)

Sandstone (Ferruginous)

Arenite (Fe-rich SiO2)

Fossilized Bone Fragment

Permineralized Vertebrate Bone (Hydrox yapatite replaced by Silica or Calcite)

Almandine Garnet in Schist

Almandine Garnet (Fe3Al2(SiO4)3) in Mica Schist

Jasper (Yellow/Brown variety)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Chalcedony (Agate/Carnelian variant)

Silicon Dioxide (SiO2)

Sandstone Beach Pebble

Clastic sedimentary rock (SiO2 with iron oxide cement)

Limonite (Iron Ore)

Limonite (FeO(OH)·nH2O)

Petrified Wood

Silicified Wood (primarily SiO2 - Silicon Dioxide)

Sandstone

Arenite (SiO2 based typically)

Red Sandstone

Arenite (Ferruginous Sandstone)

Kambaba Jasper

Rhyolite (Volcanic rock) or Stromatolite (debated)

Quartz (Clear Quartz)

Silicon Dioxide (SiO2)

Quartz Geode or Nodular Quartz

Silicon Dioxide (SiO2) in Host Matrix

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Clear Quartz Cluster

Silicon Dioxide (SiO2)

Clear Quartz

Quartz (Silicon Dioxide, SiO2)

Carnelian

Carnelian Chalcedony (SiO2 with iron oxide impurities)

Quartz (specifically Clear Quartz or Rock Crystal)

Silicon Dioxide (SiO2)

Clear Quartz

Quartz (Silicon Dioxide, SiO2)

Red Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Dyed Agate

Silicon Dioxide (SiO2)

Dalmatian Jasper

Peralkaline rhyolite

Sandstone Clast

Arenite (primarily SiO2)

Biotite Schist with Garnet

Garnet-Biotite Schist

Banded Gneiss

Gneiss (Metamorphic Rock)

Yellow Chalcedony

Cryptocrystalline Quartz (SiO2)

Ironstone Concretion

Limonitic/Hematitic Concretion

Hag Stone (Piddock bored rock)

Calcareous sedimentary rock featuring Pholadidae borings

Sandstone (Quartzose Sandstone)

Clastic sedimentary rock (SiO2 primary composition)

Chert (Jasper/Limonitic Chert)

Silicon dioxide (SiO2)

Chert (Jasper variety)

Silicon Dioxide (SiO2)