Snowflake Obsidian
Volcanic glass with Cristobalite inclusions (70–75% SiO2)
Category
Browse not a rock or mineral specimens identified by the Rock Identifier community.
Snowflake Obsidian
Volcanic glass with Cristobalite inclusions (70–75% SiO2)
Quartz Geode
Silicon Dioxide (SiO2)
Quartz Geode
Silicon Dioxide (SiO2)
Green Calcite
Calcium Carbonate (CaCO3)
Amethyst (Rough Quartz)
Silicon Dioxide (SiO2) with iron impurities
Banded Agate (Tumbled)
Agate (Variety of Chalcedony/Quartz), SiO2
Amethyst (Tumbled Stone)
Amethyst (Silicon Dioxide with Iron impurities, SiO2)
Carnelian
Carnelian (SiO2 - Chalcedony colored by Iron Oxide)
Quartzite with Chlorite/Epidote
Metamorphosed Quartzite (SiO2)
Sandstone (Ferruginous)
Arenite with Iron Oxides
Concretion with Quartz Veining
Septarian Concretion (CaCO3 / SiO2)
Sandstone (specifically Flagstone)
Arenite (primarily composed of SiO2)
Agate
Silicon Dioxide (SiO2)
Quartz Geode / Druzy Quartz
Silicon Dioxide (SiO2)
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Dyed Blue Agate
Silicon Dioxide (SiO2)
Satin Spar (Selenite)
Gypsum (CaSO4·2H2O)
Sandstone (Ferruginous)
Arenite (primarily SiO2 with iron oxide cement)
Copper-bearing Quartz (with Malachite and Iron Oxides)
Quartz (SiO2) with Malachite (Cu2CO3(OH)2) and Hematite/Limonite (Fe2O3)
Granite
Granite (Felsic intrusive igneous rock)
Sandstone (with Iron Staining)
Clastic sedimentary rock (primarily Quartz with Fe2O3 staining)
Granodiorite
Granodiorite (calc-alkaline phaneritic igneous rock)
Gneiss
Gneiss
Chakra Stone (Composite / Man-made Bonded Gemstones)
Composite of Quartz, Lapis Lazuli, Aventurine, Tiger's Eye, and Jasper (SiO2, (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2, etc.)
Sandstone (with potential iron-oxide staining)
Arenite (primarily SiO2)
Quartzite (Milky Quartz pebble)
Silicon Dioxide (SiO2)
Granitic Gneiss
Gneiss (High-grade Metamorphic Rock)
Milky Quartz with inclusions
Quartz (Silicon Dioxide, SiO2)
Sandstone
Arenite (primarily Quartz, SiO2)
Gneiss
Gneiss
Quartz (Specifically Clear to Smoky Quartz point)
Silicon Dioxide (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Clear Quartz Crystal
Quartz (Silicon Dioxide, SiO2)
Biotite (Black Mica)
Biotite [K(Mg,Fe)3(AlSi3O10)(F,OH)2]
Druzy Quartz on Agate/Chert
Silicon Dioxide (SiO2)
Granite Cobble
Phaneritic Plutonic Felsic Rock
Basalt with Weathering Crust
Extrusive mafic volcanic rock
Granite with Orthoclase and Hematite Staining
Phaneritic Felsic Igneous Rock (primarily SiO2 with KAlSi3O8)
Black Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Pink Granite
Phaneritic Felsic Igneous Rock (composed primarily of K-Feldspar, Quartz, and Plagioclase)
Pink Granite
Phaneritic Felsic Igneous Rock (composed primarily of K-Feldspar, Quartz, and Mica)
Quartzite
Quartzite (primarily SiO2)