Jasper and Quartz conglomerate (River Rock)
Silicon Dioxide (SiO2) - Chalcedony and Quartz variety
sedimentary
Category
Igneous Rock (Volcanic Glass)
Browse igneous rock (volcanic glass) specimens identified by the Rock Identifier community.
Yellow Quartz (Citrine or Iron-stained Quartz)
Silicon Dioxide (SiO2)
mineral
Red Jasper
Jasper (SiO2) with Hematite (Fe2O3) inclusions
sedimentary (microcrystalline quartz)
Quartz (Clear / Rock Crystal)
Silicon Dioxide (SiO2)
Mineral
Amethyst Quartz
Silicon Dioxide (SiO2 with iron impurities)
mineral
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Clear Quartz (Rock Crystal)
Quartz (Silicon Dioxide, SiO2)
mineral
Obsidian
Volcanic glass (high silica content, usually >70% SiO2)
igneous
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
sedimentary
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Jasper with Quartz Veining
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Milky Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
mineral
Amethyst
Amethyst (Silicon Dioxide with iron impurities), SiO2
mineral
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
mineral
Granite
Granite
Igneous
Chevron Amethyst
Silicon Dioxide (SiO2) with iron impurities
mineral
Orthoclase (Potassium) Feldspar in Quartz
KAlSi3O8 (Potassium Aluminum Silicate)
igneous
Jasper with Epidote Vein
Silicon Dioxide (SiO2) with Calcium Aluminum Iron Silicate (Ca2(Al,Fe)3(SiO4)3(OH))
sedimentary
Clear Quartz (or Rock Crystal)
Quartz (SiO₂ - Silicon Dioxide)
Mineral
Mahogany Obsidian
Volcanic glass containing Hematite or Magnetite (SiO2 + Fe2O3)
igneous
Blue Lace Agate
Chalcedony (a form of Quartz) - SiO2
Mineral
Red Jasper
Jasper (Silica/Silicon Dioxide, SiO2 plus iron inclusions)
sedimentary
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Quartz Geode
Silicon dioxide (SiO2)
mineral
Olivine (Peridot)
Magnesium Iron Silicate (Mg, Fe)2SiO4
mineral
Banded Agate (River Stone)
Agate (Silicon Dioxide - SiO2)
mineral
Druzy Quartz on Matrix
Silicon Dioxide (SiO2)
mineral
Jasper (specifically Bloodstone or Heliotrope variety)
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary (chemically precipitated)
Granite
Phaneritic Plutonic Rock (High Silica content)
igneous
Quartz Druzy (on Calcedony/Quartz base)
Silicon Dioxide (SiO2)
mineral
Magnetite
Magnetite (Fe3O4)
mineral
Quartz Geode
Silicon Dioxide (SiO2)
mineral
Orthoclase Feldspar (Salmon variety)
Orthoclase, KAlSi3O8
mineral
Jasper (Red Jasper)
Silicon Dioxide (SiO₂)
sedimentary
Quartz Vein in Host Rock (Gossanous Matrtix)
Silicon Dioxide (SiO2) with iron oxides (Limonite/Hematite)
mineral
Carnelian Agate
Silicon Dioxide (SiO2) with Iron Oxide impurities
mineral
Milky Quartz (with Iron staining)
Silicon Dioxide (SiO2)
mineral
Granite Cobble (River Stone)
Felsic intrusive igneous rock (composition: Quartz, Feldspar, Mica)
igneous
Banded Agate (specifically Sardonyx or Carnelian Agate)
Silicon Dioxide (SiO2) - Chalcedony variety
mineral
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Milky Quartz with inclusions
Quartz (Silicon Dioxide, SiO2)
mineral
Tree Agate (or Moss Agate)
Dendritic Agate (Silicon Dioxide - SiO2)
mineral