Quartz (Iron-stained)
Silicon Dioxide (SiO2)
mineral
Category
Mineral, Often A Rock Given Its Aggregate Nature
Browse mineral, often a rock given its aggregate nature specimens identified by the Rock Identifier community.
Sandstone (with Iron Staining)
Clastic Sedimentary Rock (primarily SiO2 with FeO(OH) impurities)
sedimentary
Dyed Agate
Silicon Dioxide (SiO2) with artificial pigment
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Shale with Iron Oxide Staining
Fissile Mudstone (primarily clay minerals and quartz)
sedimentary
White Chalcedony (likely Common Opal or Milky Quartz)
Silicon Dioxide (SiO2)
mineral
Quartz with Chalcopyrite and Pyrite
Silicon Dioxide (SiO2) with Copper Iron Sulfide (CuFeS2)
mineral
Tree Agate
Silicon Dioxide (SiO2) with Dendritic Inclusions
Mineral
Basalt
Extrusive mafic igneous rock
igneous
Gneiss
Gneiss
metamorphic
Pink Anthracite Coal (dyed)
Anthracite Coal (Artificially Colored)
Sedimentary Rock (Altered)
Sandstone (with potential trace fossils)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Carnelian (Chalcedony variety)
SiO2 (Silicon Dioxide)
Mineral
Ferruginous Sandstone
Arenite with Iron-oxide cement (composed of Quartz and Limonite/Hematite)
sedimentary
Chinese Writing Stone
Porphyritic Basalt or Porphyritic Andesite with Feldspar phenocrysts (SiO2-rich Silicates)
igneous
Quartz (Vein Quartz)
Silicon Dioxide (SiO2)
mineral
Schist
Mica Schist
metamorphic
Basalt (River Pebble)
Extrusive mafic igneous rock
igneous
Green Glass Cullet / Recycled Glass
Amorphous Silicon Dioxide (SiO2) with various metal oxides
Man-made Glass (Not a natural rock or mineral)
Golden Healer Quartz
Ferruginous Quartz (SiO2 with Fe2O3 inclusions)
mineral
Blue Sapphire (Tumbled/Polished)
Corundum (Al2O3)
mineral
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
mineral
Milky Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
mineral
Quartz Geode
Silicon Dioxide (SiO2)
mineral
Quartz Geode (Cracked Open)
Quartz (Silicon Dioxide - SiO2)
mineral
Red Tiger's Eye
SiO2 (Silicon Dioxide with iron inclusions)
mineral
Red Jasper
Jasper (Silicon Dioxide, SiO2 with Fe2O3 inclusions)
mineral
Basalt
Basalt (Mafic volcanic rock)
igneous
Carnelian (Red Chalcedony)
Silicon Dioxide (SiO2) - variety of Chalcedony
mineral
Quartz (Smoky or Impure Variety)
Silicon Dioxide (SiO2)
mineral
Gneiss (Granitic Gneiss)
Gneiss (from German Gneis, related to 'spark')
metamorphic
Basalt
Mafic Volcanic Rock (composed of plagioclase, pyroxene, and olivine)
Igneous
Milky Quartz (Druzy Geode fragment)
Silicon Dioxide (SiO2)
mineral
Granite
Granite (Phaneritic Quartz-Feldspar Plutonic Rock)
igneous
Flower Agate (Plume Agate)
Chalcedony (Silicon Dioxide) with Spherulitic Inclusions - SiO2
mineral
Basalt with Plagioclase Phenocrysts
Porphyritic Basalt
igneous
Hypersthene
Hypersthene (formula: (Mg,Fe)SiO3)
mineral
Sandstone (Ferruginous)
Arenite (composed primarily of SiO2 with Fe2O3 staining)
sedimentary
Jasper with Quartz Veining
Silicon Dioxide (SiO2) - Opaque cryptocrystalline variety of Quartz
sedimentary
Quartzite with inclusions
Quartzite (primarily SiO2)
metamorphic