Igneous Rock (Volcanic Glass)

Milky Quartz (Water-worn Pebble)

Silicon Dioxide (SiO2)

Blue Lace Agate

Chalcedony (SiO2) with trace inclusions

Fire Opal (Common/Precious in Matrix)

Hydrated Silica (SiO2·nH2O)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Rough Quartz (or Quartzite pebble)

Silicon Dioxide (SiO2)

Agate Geode

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Quartz (Silicon Dioxide, SiO2)

Quartz Geode Fragment

Silicon Dioxide (SiO2)

Fire Agate

Chalcedony (Silicon Dioxide, SiO2) with Limonite/Goethite

Banded Agate (Onyx variety)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

River Pebbles (Tumbled Quartz and Basalt)

Silicon Dioxide (SiO2) for white quartz; Mafic Volcanic Rock for basalt

Granite

Granite (composed mainly of Quartz, Feldspar, and Mica)

Yellow Jasper

Silicon Dioxide (SiO2) - Opaque Chalcedony

Amethyst

Quartz variety; chemical formula: SiO₂ (silicon dioxide) with Fe³⁺ impurities

Jasper and Basalt (Mixed Breccia or Chert)

Silicon Dioxide (SiO2) with Ferromagnesian silicates

Quartz Druze (on Matrix)

Silicon Dioxide (SiO2)

Agate

Silicon Dioxide (SiO2) - variety Chalcedony

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Quartz (Clear Quartz/Rock Crystal)

Silicon Dioxide (SiO2)

Green Slag Glass

Amorphous Silicon Dioxide (with metallic impurities)

Yellow Quartz (Citrine/Yellow Jasper mix)

Silicon Dioxide (SiO2) with iron oxide inclusions

Quartz Pebble (Chalcedony/Agate variety)

Silicon Dioxide (SiO2)

Peridot (Olivine)

(Mg,Fe)2SiO4 (Magnesium Iron Silicate)

Snowflake Obsidian

Volcanic glass (SiO2 - Silicon Dioxide with Cristobalite inclusions)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Granodiorite

Granodiorite

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Granodiorite

Granodiorite (containing Plagioclase, Quartz, and Biotite)

Quartz (Clear Quartz/Rock Crystal)

Silicon Dioxide (SiO2)

Jasper (likely Ocean Jasper or Variegated Jasper)

Silicon Dioxide (SiO2) with impurities

Quartz Druzy on Matrix (likely Agate or Jasper)

Silicon Dioxide (SiO2) with various mineral inclusions

Olivine (Peridot)

Magnesium Iron Silicate ((Mg, Fe)2SiO4)

Basalt

Basalt

Amethyst (Geode)

Silicon Dioxide with Iron impurities (SiO2)

Lapis Lazuli (blue bead) and Moss Agate (green heart)

Lapis Lazuli (lazurite-based rock) and Moss Agate (SiO2 with manganese/iron inclusions)

Red Jasper (Opaque Chalcedony)

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

Jasper Agate (specifically Brecciated Jasper with Agate inclusions)

Silicon Dioxide (SiO2)

Red Jasper (specifically Brecciated Jasper)

Silicon Dioxide (SiO2) with Hematite inclusions

Red Granite

Phaneritic Felsic Intrusive Igneous Rock (primarily K-feldspar, Quartz, and Biotite)

Granite Pebble (Salt and Pepper Granite)

Phaneritic Felsic Igneous Rock (primarily Quartz, Feldspar, and Biotite/Amphibole)

Mixed Tumbled Gemstones and River Rocks

Mixed Decorative Stones (predominantly Silicon Dioxide - SiO2 variants)