Mineral Like (Natural Glass)

Sandstone

Arenite (primarily SiO2)

Clear Quartz

Quartz (Silicon Dioxide, SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Milky Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Chert (with Drusy Quartz Pocket)

Silicon Dioxide (SiO2)

Granite Pebble

Granite (Phaneritic intrusive igneous rock)

Chert (Flint) Pebble

Microcrystalline Quartz (SiO2)

Rose Quartz

Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese

Clear Quartz

Quartz (Silicon Dioxide, SiO2)

Diamond

Carbon (C)

Milky Quartz with Mineral Inclusions

Quartz (Silicon Dioxide, SiO2)

Quartz Sand/Gravel

Silicon Dioxide (SiO2)

Quartz

Silicon dioxide (SiO2)

Sandstone (Water-worn Pebble)

Clastic sedimentary rock (primarily SiO2)

Conglomerate

Conglomerate (clastic sedimentary rock)

Silver Sheen Obsidian

Volcanic Glass (Amorphous Silicon Dioxide - SiO2 with impurities)

Pearl

Organic Mineral (CaCO3 with conchiolin)

Diamond

Diamond (pure carbon, C)

Quartz (Chert/Chalcedony flake)

Silicon Dioxide (SiO2)

Pyrite

Iron Disulfide (FeS2)

Pink Quartz

Silicon Dioxide (SiO2) with trace inclusions

Dyed Purple Agate

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Greenstone / Epidosite

Epidosite (Metasomatic rock consisting mainly of Epidite Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH) and Quartz)

Rose Quartz

Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese

Chert (Flint)

Chert (SiO2)

Ferruginous Quartz

Silicon Dioxide with Iron Oxide inclusions (SiO2 + Fe2O3/FeO(OH))

Sandstone (Ferruginous)

Arenite (with Goethite/Limonite cement)

Quartzite

Quartzite (High-purity SiO2)

Chalcedony (Quartz Var.)

Silicon Dioxide (SiO2)

Quartz (Massive Quartz or Quartzite)

Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Amethyst

Amethyst (Silicon Dioxide, SiO2) with iron impurities

Milk Quartz (with Iron staining)

Silicon Dioxide (SiO2)

Clear Quartz

Quartz (Silicon Dioxide, SiO2)

Clear Quartz

Quartz (Silicon Dioxide, SiO2)

Milky Quartz with Iron Staining

Silicon Dioxide (SiO2)

Pink Dyed Agate (Banded Chalcedony)

Silicon dioxide (SiO2) - variety Chalcedony

Orange Quartz with Hematite inclusions

Quartz (SiO2) with Hematite (Fe2O3) inclusions

Ferruginous Sandstone with Quartz Inclusions

Clastic Sedimentary Rock (Iron-rich Sandstone)

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Clear Quartz

Silicon Dioxide (SiO2)