None

Clear Quartz Cluster

Quartz (Silicon Dioxide - SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Quartz (Druzy)

Silicon Dioxide (SiO2)

Grey River Pebble (Likely Quartz-rich or Limestone)

Clastic Sedimentary Rock (typically SiO2 or CaCO3 based)

Milky Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Amethyst

Amethyst (Silicon Dioxide - SiO2 with Iron impurities)

Quartzite

Quartzite (mostly SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Quartz Pebble (Geode-like)

Silicon Dioxide (SiO2)

Mineral

Agate Geode

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Amethyst

Amethyst (Silicon Dioxide, SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Citrine Quartz

Citrine (Silicon Dioxide, SiO2)

Rose Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Quartzite (or Milky Quartz pebble)

Quartzite (Metamorphosed Sandstone) / Silicon Dioxide (SiO2)

Amethyst

Amethyst (Silicon Dioxide containing trace Iron impurities, SiO2)

Red Garnet (likely Almandine)

Almandine (Fe3Al2(SiO4)3)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Yellow Quartzite

Quartzite (SiO2)

Clear Quartz (Tumbled)

Quartz (Silicon Dioxide - SiO2)

Quartz

Silicon Dioxide (SiO2)

Red Chert (Jasper)

Cryptocrystalline Quartz (SiO2) with iron oxide inclusions

Flint (Chert)

Cryptocrystalline Quartz (SiO2)

Amethyst Cluster

Amethyst (Silicon Dioxide), chemical formula: SiO2

Quartz (Smoky/Milky variety)

Silicon Dioxide (SiO2)

White Quartz

Silicon Dioxide (SiO2)

Banded Quartz

Silicon Dioxide (SiO2)

Chert (Nodule)

Microcrystalline Quartz (SiO2)

Quartz (Chert/Chalcedony variety)

Silicon Dioxide (SiO2)

Chert / Flint

Chert (Microcrystalline Quartz, SiO2)

Sandstone (Quartz-rich)

Arenite (composed primarily of SiO2)

Ferruginous Quartz (Iron-stained Quartz)

Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions

Basalt (Fieldstone)

Basalt

igneous

Chert Concretion (with typical hematite/limonite staining)

Sedimentary Concretion (SiO2 with FeO(OH)⋅nH2O)

Pink Quartzite

Quartzite (primarily SiO2 with trace impurities of iron oxides)