Opalite
Man-made Synthetic Glass (Silicon Dioxide with metal additives)
mineral
Category
Mineral Like Byproduct (Often Mistaken For Igneous Rock Or Meteorite)
Browse mineral like byproduct (often mistaken for igneous rock or meteorite) specimens identified by the Rock Identifier community.
Greenstone
Metabasalt / Chlorite-Epidote Schist
metamorphic
Gneiss
Gneiss (High-grade regional metamorphic rock)
metamorphic
Granitic Pegmatite
Granite Pegmatite (principally KAlSi3O8, SiO2, and KAl2(AlSi3O10)(OH)2)
igneous
Biotite or Phlogopite Mica
K(Mg,Fe)3(AlSi3O10)(F,OH)2
mineral
Gneiss (specifically a weathered Amphibolite or Garnet Gneiss)
Gneiss (complex silicate composition)
metamorphic
Scoria (Vesicular Basalt)
Scoria (Extrusive Igneous Rock)
igneous
Peridot
Olivine ((Mg,Fe)2SiO4)
Mineral
Queen Conch Shell (Biogenic Calcium Carbonate)
Aliger gigas (synonym Strombus gigas); Composition: Aragonite (CaCO3)
mineral
Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
metamorphic
Amygdaloidal Basalt
Amygdaloidal Basalt (extrusive volcanic rock with mineral inclusions)
igneous
Olivine-bearing Basalt / Scoria
Mafic Igneous Rock (primarily (Mg, Fe)2SiO4)
igneous
Iron-stained Quartz
Silicon Dioxide (SiO2) with Hematite/Limonite impurities
mineral
Ferruginous Quartz (Iron-stained Quartz)
Silicon Dioxide (SiO2) with iron oxide inclusions/staining (Limonite/Hematite)
Mineral
Granodiorite
Granodiorite
igneous
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Basalt with Quartz Veins
Basalt (complex silicate) with Quartz (SiO2) intrusions
igneous
Peridot
Olivine (Magnesium Iron Silicate), (Mg, Fe)2SiO4
mineral
Epidosite (Epidote-rich rock)
Epidosite (consisting primarily of Epidote: {Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH))
metamorphic
Granite (Weathered)
Plutonic Igneous Rock (Granitic)
igneous
Granite Pebble (Weathered)
Phaneritic Felsic Igneous Rock
igneous
Epidote
Epidote Group (Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH))
metamorphic
Snowflake Obsidian
Volcanic glass with Cristobalite inclusions (70–75% SiO2)
igneous
Quartz Vein in Host Rock (Pebble)
Quartz (SiO2) with sandstone or siltstone matrix
metamorphic/igneous transition
Basalt
Basalt (extrusive igneous rock)
Igneous
Sandstone
Clastic sedimentary rock (primarily SiO2)
sedimentary
Sandstone Concretion
Moqui Marble / Iron-oxide Concretion (SiO2 with Hematite/Goethite)
sedimentary
Conglomerate
Conglomerate (a clastic sedimentary rock)
Sedimentary Rock
Olivine (Peridot)
Magnesium Iron Silicate ((Mg, Fe)2SiO4)
mineral
Blue Quartzite (Blue Aventurine / Dumortierite Quartz)
Quartzite with inclusions (SiO2 with AlAl4BSi3O18)
metamorphic
Basalt
Basalt (Aphanitic Mafic Igneous Rock)
igneous
Magnetite Orthorthotropic Rock
Magnetite (Fe3O4)
mineral
Druzy Agate (specifically Black Druzy Agate)
Silicon Dioxide (SiO2)
mineral
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic Extrusive)
igneous
Gneiss (Pebble)
Gneiss
metamorphic
Granite
Granite (a common rock type, not a single mineral with a formula. Composed primarily of quartz, feldspar, and mica/amphibole).
igneous
Pumice
Pumice (Vitreous volcanic rock)
igneous
Granite
Granite (a plutonic igneous rock composed of quartz, feldspar, and mica)
igneous
Granite Pebble
Felsic Intrusive Igneous Rock (composed of Quartz, Alkali Feldspar, and Plagioclase)
igneous
Clear Quartz Crystal
Quartz (Silicon Dioxide, SiO2)
mineral
Quartz
Quartz (SiO₂)
Mineral
Quartz (likely Milky Quartz or Chalcedony)
Quartz (SiO2 - Silicon Dioxide)
Mineral