Obsidian
Volcanic Glass (SiO2 - Silicon Dioxide with impurities)
Igneous
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.
Basalt
Mafic volcanic rock (primarily plagioclase feldspar and pyroxene)
igneous
Geode (Unopened)
Siliceous Concretion / Geode
sedimentary
Banded Chalcedony (Agate)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
mineral
Quartz Vein in Host Rock
Silicon Dioxide (SiO2)
mineral with metamorphic or sedimentary host
Basalt
Basalt
igneous
Granitic Quartz with Feldspar
Granite (composed primarily of SiO2 and KAlSi3O8)
igneous
Sandstone
Arenite
sedimentary
Basalt
Mafic Volcanic Basalt (Major minerals: Plagioclase feldspar, Pyroxene; Minor: Olivine, Magnetite)
igneous
Basalt
Extrusive mafic igneous rock
igneous
Granite Cobble
Phaneritic Felsic Igneous Rock
igneous
Amygdaloidal Basalt
Amygdaloidal Basalt
igneous
Orthoclase Feldspar (or K-Feldspar)
Orthoclase (KAlSi3O8)
Mineral
Gneiss (specifically Banded Gneiss)
Gneiss
metamorphic
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
mineral
Aquamarine and clear quartz
Aquamarine (Be3Al2Si6O18), Quartz (SiO2)
Mineral
Basalt
Mafic Igneous Rock (composed primarily of Pyroxene and Plagioclase Feldspar)
Igneous
Goldstone
N/A (Synthetic Glass with Copper Inclusions)
Manufactured Glass
Granite
Granite (Mainly Quartz, Alkali Feldspar, and Plagioclase)
igneous
Porphyry (specifically Porphyritic Rhyolite or Andesite)
Porphyritic Igneous Rock (composed of Phenocrysts in an Aphanitic groundmass)
igneous
Granite
Granite (Felsic Plutonic Rock)
Igneous
Ruby in Zoisite (Anyolite)
Corundum var. Ruby in Zoisite (Al2O3 + (Ca2Al3(SiO4)3(OH)))
metamorphic
Pumice
Pumice (a highly vesicular volcanic rock)
igneous
Smoky Quartz
Smoky Quartz (Silicon Dioxide - SiO2)
mineral
Fluorite
Calcium Fluoride (CaF2)
mineral
Chrysoprase
Silicon Dioxide (Nickel-bearing Chalcedony) - SiO2
mineral
Rhyolite
Rhyolite (High-silica volcanic rock)
igneous
Note: Item is not a geological specimen
Guitar Components (Steel, Nickel, Plastic, Wood)
Synthetic/Consumer Product
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Clear Quartz (beads in a bracelet)
Quartz (SiO2)
Mineral
Red Garnet (Almandine-Pyrope series)
Garnet Group, Almandine (Fe3Al2(SiO4)3) or Pyrope (Mg3Al2(SiO4)3)
mineral
Ferruginous Quartz
Silicon Dioxide (SiO2) with Hematite/Limonite impurities
mineral
Banded Agate (Chert/Chaldcedony)
Silicon Dioxide (SiO₂)
mineral
Turquoise
CuAl6(PO4)4(OH)8·4H2O (Hydrated copper and aluminium phosphate)
mineral
Sandstone (Quartzose)
Sandstone (clastic sedimentary rock, primarily SiO2)
sedimentary
Red Sandstone
Sandstone (principally Quartz with Iron Oxide coating)
sedimentary
Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
metamorphic
Milky Quartz with Iron Staining
Quartz (Silicon Dioxide, SiO2)
mineral
Sandstone (Ferruginous)
Arenite (primarily SiO2 with iron oxide cement)
sedimentary
Green Fluorite
Fluorite (Calcium Fluoride, CaF2)
mineral
Quartz (Clear Quartz/Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Pink Granite
Phaneritic intrusive igneous rock (K-feldspar rich)
igneous