Man Made Rock (Sedimentary Analogue)

Calamites (Fossilized Horsetail)

Calamites suckowii (Family: Calamitaceae)

Quartz Vein in Host Rock (Likely Slate or Shale)

Hydrothermal Quartz (SiO2) in Pelitic host rock

Limestone

Calcium Carbonate (CaCO3)

Clear Quartz (Rock Crystal)

Quartz (Silicon Dioxide, SiO2)

Red Sandstone (Iron-rich Sandstone)

Clastic Sedimentary Rock - Quartz Arenite / Arkose with Hematite Cement

Almandine Garnet

Almandine (Fe3Al2Si3O12)

Gneiss

Gneiss (High-grade metamorphic rock)

Sandstone (Ferruginous)

Arenite (primarily SiO2 with Fe2O3 cement)

Chert (Banded)

Chert (Microcrystalline Silicon Dioxide, SiO2)

Agate Geode / Nodular Chalcedony

Silicon Dioxide (SiO2) with impurities

Druzy Quartz on Ironstone

Silicon Dioxide (SiO2) on Limonitic Ironstone

Red Sandstone

Clastic sedimentary rock (primarily SiO2 with Fe2O3 iron oxide staining)

Sandstone (Ferruginous)

Arenite with Iron Oxide cement (primarily SiO2 with Fe2O3)

Quartz Geode Fragment

Silicon Dioxide (SiO2)

Sandstone (Ferruginous/Red Sandstone)

Clastic sedimentary rock (primarily SiO2 with Fe2O3)

Quartz Geode

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Schist

Mica Schist (Metamorphic Rock)

Sandstone (likely Graywacke or Lithic Sandstone)

Arenite / Wacke (SiO2 based with lithic fragments)

Quartz Geode (Cracked Open Fragment)

Silicon Dioxide (SiO2)

Pink Chalcedony (Agate/Jasper blend)

Silicon Dioxide (SiO₂)

Agate (specifically Chalcedony nodule)

Silicon Dioxide (SiO2)

Gneiss

Gneiss (High-grade Metamorphic Rock)

Sandstone

Arenite (Sedimentary rock composed of sand-sized grains)

Quartz Drusy on Matrix

Silicon Dioxide (SiO2)

Chert (and/or Flint)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Granite Gneiss

Gneiss (quartz-feldspar dominated)

Jasper

Jasper (Silicon Dioxide, SiO2 plus iron oxide impurities)

Sandstone

Arenite (primarily SiO2)

Granite Gneiss

Felsic Gneiss

Pyritic Sandstone

Clastic Sedimentary Rock (Pyrite-bearing Sandstone)

Manganese-coated Sandstone

Clastic sedimentary rock with Manganese Oxide (often Pyrolusite or Psilomelane)

Red Sandstone

Clastic Terrigenous Sedimentary Rock (composed mostly of SiO2 with Fe2O3)

Mica Schist with Garnet

Garnetiferous Mica Schist

Sandstone Beach Pebble

Clastic Sedimentary Rock (primarily Quartz with Iron Oxide coating)

Chert (Grey-Green Var.)

Silicon Dioxide (SiO2)

Leopard Skin Jasper

Silicon Dioxide (SiO2) with impurities

Red Sandstone

Clastic sedimentary rock (primarily SiO2 with Fe2O3)

Quartz (Druzy/Macro-crystalline)

Silicon Dioxide (SiO2)

Mica Schist

Mica Schist (Schistose metamorphic rock rich in Muscovite/Biotite)

Mica Schist

Crystalline Schist (often containing Muscovite, Biotite, and Quartz)

Chert Nodules in Limestone

Microcrystalline Quartz (SiO2) within Calcium Carbonate (CaCO3)