Tektite (Natural Glass)

Clear Quartz

Quartz (Silicon Dioxide, SiO2)

Massive Quartz (Yellow/Citrine variety)

Silicon Dioxide (SiO2)

Amethyst

Silicon dioxide (SiO2)

Rose Quartz

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

Yellow Quartz (Citrine/Yellow Jasper mix)

Silicon Dioxide (SiO2) with iron oxide inclusions

Citrine

Silicon Dioxide (SiO2) - Yellow Quartz variety

Jasper

Silicon dioxide / Chalcedony (SiO2)

Sandstone (with Iron concretions/staining)

Arenite (composed primarily of Quartz and Feldspar with Iron Oxide cement)

Clear Quartz Crystal

Quartz (Silicon Dioxide, SiO2)

Chert (Flint variety)

Chert (Cryptocrystalline Quartz, SiO2)

Amethyst and Citrine (Quartz variants)

Silicon Dioxide (SiO2)

Natural or Cultured Pearl

Calcium Carbonate (Aragonite and Conchiolin), CaCO3

Emerald

Beryl (Be3Al2Si6O18) with trace amounts of Chromium and/or Vanadium

Amethyst

SiO2 (Amethyst is a variety of Quartz)

Smoky Quartz

Smoky Quartz (Silicon Dioxide, SiO2)

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Jasper and Yellow Chert (Tumbled)

Microcrystalline Quartz (SiO2)

Smoky Quartz

Smoky Quartz (Silicon Dioxide, SiO2)

Amethyst (Quartz Cluster)

Silicon Dioxide (SiO2) with iron impurities

Jasper or Agate-bearing Chert

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Pink Sapphire

Corundum (Al2O3 with trace Chromium and Iron)

Granite (Background) and Quartzite/River Pebble (Foreground Heart)

Phaneritic Felsic Igneous Rock (Granite background)

Ferrosilicon Slag (Industrial Vitrified Glass)

Vitreous Silicate Residue

Citrine

Quartz (SiO₂)

Amethyst

Amethyst (variety of Quartz, SiO2)

Yellow Quartz Pebble

Silicon Dioxide (SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Smoky Quartz

Silicon Dioxide (SiO2)

Amethyst

Silicon Dioxide (SiO2) with trace Iron impurities

Yellow Quartz (Citrine or Iron-stained Quartz)

Silicon Dioxide (SiO2)

Quartzite

Quartzite (primarily SiO2)

Banded Agate (specifically Sardonyx or Carnelian Agate)

Silicon Dioxide (SiO2) - Chalcedony variety

Milk Quartz (Tumbled Pebble)

Quartz (Silicon Dioxide, SiO2)

Sandstone (Quartz Sandstone)

Arenite (primarily SiO2)

Diamond (or Lab-Grown Cubic Zirconia)

Carbon (C)

Clear Quartz (Rock Crystal)

Quartz (Silicon Dioxide, SiO2)

Smoky Quartz and Clear Quartz Geode

Silicon Dioxide (SiO2)

Citrine

Silicon Dioxide (SiO2)

Sandstone

Arenite

Amethyst

Amethyst (Silicon Dioxide, SiO2 with Iron impurities)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Chert (Jasper variety) with Iron Oxide staining

Cryptocrystalline Quartz (SiO2) with Goethite/Limonite impurities