Sedimentary Rock (Altered)

Sandstone (with biological crust)

Arenite (SiO2 based)

Almandine Garnet in Schist

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

Sandstone

Arenite (primarily SiO2 - Silicon Dioxide)

Banded Gneiss

Gneiss (Metamorphic Rock)

Clear Quartz

Quartz (Silicon Dioxide, SiO2)

Clear Quartz Cluster

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Picture Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Quartz (specifically Clear Quartz or Rock Crystal)

Silicon Dioxide (SiO2)

Chert with Desert Varnish

Cryptocrystalline Quartz (SiO2) with Manganese/Iron oxide coating

Clear Quartz

Quartz (Silicon Dioxide, SiO2)

Banded Calcite (Green Onyx)

Calcium Carbonate (CaCO3)

Carnelian

Carnelian Chalcedony (SiO2 with iron oxide impurities)

Dyed Agate

Silicon Dioxide (SiO2)

Red Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Dalmatian Jasper

Peralkaline rhyolite

Chert (Yellow Jasper/Flint)

Microcrystalline Quartz (SiO2)

Sandstone (Quartzose Sandstone)

Clastic sedimentary rock (SiO2 primary composition)

Quartz Geode

Silicon Dioxide (SiO2) within a geode

Hag Stone (Piddock bored rock)

Calcareous sedimentary rock featuring Pholadidae borings

Biotite Schist with Garnet

Garnet-Biotite Schist

Limestone

Calcium Carbonate (CaCO3)

Ironstone Concretion

Limonitic/Hematitic Concretion

Sandstone Beach Pebble

Clastic sedimentary rock (SiO2 with iron oxide cement)

Jasper (Yellow/Brown variety)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Halite (Rock Salt)

Halite (Sodium Chloride, NaCl)

Gneiss

Gneiss

Sandstone (Red Sandstone)

Clastic Sedimentary Rock (primarily SiO2 with Iron Oxide)

Sandstone (Ferruginous)

Arenite (iron-rich)

Chert / Flint Conglomerate

Silicified Sedimentary Breccia (primarily SiO2)

Gneiss (with Quartzite and Biotite)

Gneiss containing SiO2 (Quartz), K(Mg,Fe)3AlSi3O10(OH)2 (Biotite), and (K,Na,Ca)AlSi3O8 (Feldspar)

Sandstone (Ferruginous)

Clastic sedimentary rock (primarily SiO2 with Fe2O3 cement)

Sandstone (Ferruginous)

Ferruginous Sandstone (SiO2 with Fe2O3)

Chert (Nodular)

Chert (SiO2 - Microcrystalline Quartz)

Chert / Flint

Cryptocrystalline Quartz (Silicon Dioxide, SiO2)

Fossil Sand Dollar (Echinoidea)

Phylum Echinodermata, Class Echinoidea (likely Dendraster or Scutella)

Yellow Chalcedony (common opal or chert variant)

Silicon Dioxide (SiO2)

Sandstone (Ferruginous)

Clastic sedimentary rock (primarily SiO2 with Fe2O3 cement)

Vuggy Quartz on Matrix

Silicon Dioxide (SiO2)

Carnelian

Carnelian (Chalcedony / SiO2)

Mixed collection of Quartz varieties, Chalcedony, and metamorphic pebbles

Mixed gemstones (primarily Silicon Dioxide - SiO2)

Ironstone Concretion (Moqui Marble variety)

Ferruginous Sandstone Concretion