Obsidian
Obsidian (principally SiO2 - Silicon Dioxide)
Category
Browse mineral like byproduct (technogenic) specimens identified by the Rock Identifier community.
Obsidian
Obsidian (principally SiO2 - Silicon Dioxide)
Scoria (Lava Rock)
Vesicular Basalt / Scoria
Pink Granite (Potassium-rich Granite)
Phaneritic Felsic Igneous Rock (primarily SiO2, Al2O3, K2O)
Satin Spar (Satin Spar Selenite)
Gypsum (CaSO4·2H2O)
Sandstone
Sedimentary rock composed mainly of sand-sized minerals or rock grains
Orthoclase Feldspar
Orthoclase (KAlSi₃O₈)
Malachite in Host Rock
Cu2CO3(OH)2
Collection of Minerals and Ores
Various (e.g., Uraninite (U3O8), Carbon (C), Native Gold (Au), Hematite (Fe2O3), Galena (PbS), etc.)
Limonite (Iron Ore)
Hydrated iron(III) oxide-hydroxide (FeO(OH)·nH2O)
Granite
Phaneritic Acidic Igneous Rock (composed of Quartz, Alkali Feldspar, and Plagioclase)
Quartz Pebble
Silicon Dioxide (SiO2)
Quartz with Mica (Muscovite or Biotite)
Silicon Dioxide (SiO2) with Phyllosilicates
Emerald in Matrix
Beryl (Be3Al2Si6O18) with Chromium impurities
Sandstone with Liesegang Rings
Clastic Sedimentary Rock with Iron Oxide Precipitates (SiO2 + Fe2O3)
Sandstone (Iron-stained)
Arenite with Limonite/Hematite staining
Chalcedony (Botryoidal)
Silicon Dioxide (SiO2)
Granitic Pegmatite (with Pink Feldspar and Quartz)
Pegmatite (KAlSi3O8 + SiO2)
Quartz / Agate Nodule
Silicon Dioxide (SiO2)
Granite Pebble
Granite (Plutonic Igneous Rock)
Diorite (Salt and Pepper Rock)
Diorite
Quartz with Tourmaline Inclusions (Tourmalinated Quartz)
SiO2 with complex borosilicate inclusions
Sandstone (with Iron Staining)
Arenite (SiO2 with Fe2O3/FeOOH impurities)
Red Sandstone
Arenite (Fe2O3 enriched)
Fossilized Shark Tooth (Drum Fish Tooth/Pavement Tooth)
Sparidae or Sciaenidae (Crushing plate dental fossil)
Quartz pebble
Silicon dioxide (SiO2)
Sandstone (with potentially metamorphic or basaltic bands)
Arenite / Lithic Wacke
Schist
Mica Schist (Group of medium-grade metamorphic rocks)
Quartz (Milky or Cloudy)
Silicon Dioxide (SiO2)
Citrine (tumbled)
Silicon dioxide, SiO2
Rough Garnet (Almandine)
Almandine Garnet (Fe3Al2(SiO4)3)
Citrine (Tumbled Quartz)
Silicon Dioxide (SiO2)
Quartz Geode
Silicon Dioxide (SiO2)
Orange Quartz
Silicon Dioxide (SiO2)
Labradorite rough fragment
(Ca,Na)[Al,Si]A̲₁O₈
Milky Quartz
Silicon Dioxide (SiO2)
Smoky Quartz and Citrine
Silicon Dioxide (SiO2)
Dyed Agate
SiO2 (Silicon Dioxide) - Chalcedony variety
Dyed Agate
SiO2 (Silicon Dioxide)
Dyed Quartz Geode
Dyed crystalline quartz (Silicon Dioxide, SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Quartz pebble
Silicon dioxide (SiO2)