Sedimentary Rock (Specifically A Concretion Or Possibly A Geode)

Clear Quartz

Silicon Dioxide (SiO2)

Sandstone (Quartz-rich)

Arenite (SiO2 based clastic rock)

Chert (specifically Gray/Tan Bedded Chert)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Gneiss

Gneissic Metamorphic Rock (Mineral composition: Quartz, Feldspar, Amphibole/Biotite)

Chert Pebble with Quartz Veins

Microcrystalline Quartz (SiO2)

Conglomerate (Asphaltic/Anthropogenic)

Clastic sedimentary rock / Bituminous mixture

Clear Quartz Cluster

Silicon Dioxide (SiO2)

Pink Granite

Phaneritic Felsic Igneous Rock (Rich in K-Feldspar)

Gneiss Pebble

Gneiss

Greywacke (River Siltstone)

Lithic Sandstone / Greywacke

Chert (Jasper or Flint variant)

Chert (composed of microcrystalline quartz, SiO2)

Botryoidal Black Chalcedony Geode (Black Grape Agate)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Red Sandstone

Clastic sedimentary rock (primarily SiO2 with Fe2O3)

Jasper (specifically Red Jasper or Iron-stained Chert)

Silicon dioxide (SiO2) with iron oxide inclusions

Ferruginous Conglomerate

Ferruginous Conglomerate (Clastic Sedimentary Rock)

Smoky Quartz on Feldspar (Granite Pegmatite)

Silicon Dioxide (SiO2) with Potassium Aluminum Silicate (KAlSi3O8)

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Carnelian

Carnelian (SiO2 variant)

Quartz

Quartz (SiO2, Silicon Dioxide)

Gneiss

Gneiss (High-grade regional metamorphic rock)

Pink Granite

Granite (Alkali-feldspar granite)

Puddingstone

Conglomerate (specifically a type of jasper conglomerate or quartz conglomerate)

Conglomerate

Clastic sedimentary rock (Polymictic Conglomerate)

Quartz Geode Fragment

Silicon Dioxide (SiO2)

Celestite (Celestine)

Celestine (Strontium Sulfate, SrSO4)

Amethyst

SiO2 (Silicon Dioxide)

Red Jasper (specifically Brecciated Jasper)

Silicon Dioxide (SiO2) with Hematite inclusions

Carnelian

Carnelian (SiO2)

Limestone

Calcium Carbonate (CaCO3)

Agate (Geode nodule)

Cryptocrystalline Quartz (SiO2)

Moss Agate

Silicon Dioxide (SiO2) with inclusions

Celestite (Celestine)

Strontium sulfate (SrSO4)

Banded Agate

Chalcedony / Silicon Dioxide (SiO2)

Ironstone concretion / Limonitic Sandstone

Goethite/Hematite Cemented Sandstone (Hydrated Iron Oxide)

Quartz Geode Pebble

Silicon Dioxide (SiO2)

Pink Granite

Phaneritic Felsic Igneous Rock (Granite)

Crushed Limestone

Sedimentary Calcium Carbonate (CaCO3)

Dyed Quartz Geode

Silicon Dioxide (SiO2) with artificial pigment

Amethyst (Purple Quartz)

Silicon Dioxide (SiO2) with iron impurities

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Moqui Marble

Ironstone Concretion (Limonite/Hematite over Sandstone)

Sandstone Moqui Marble (Concretion)

Iron oxide concretion (Hematite/Goethite and Quartz)