Milky Quartz (Water-worn Pebble)
Silicon Dioxide (SiO2)
Category
Browse igneous rock (volcanic glass) specimens identified by the Rock Identifier community.
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)