Obsidian
Obsidian (Volcanic glass), SiO2 (major component)
igneous
Category
Not A Rock (Animated Character)
Browse not a rock (animated character) specimens identified by the Rock Identifier community.
Biotite Mica
K(Mg,Fe2+)3(Al,Fe3+)Si3O10(OH,F)2
Mineral
Green Aventurine
Quartz (Aventurine variety) - SiO₂ with Fuchsite inclusions
Mineral
Amethyst/Smoky Quartz Cluster
Silicon Dioxide (SiO2)
mineral
Amethyst Geode/Cluster
Quartz (SiO2) - variety Amethyst
Mineral
Pyrite (or Fool's Gold)
Pyrite (FeS₂)
Mineral
Chrysoprase
Chalcedony (cryptocrystalline SiO2 variety)
Mineral
River Pebble (Likely Chert or Fine-Grained Sandstone/Quartzite)
Siliciclastic clast (likely Chert or Quartzarenite/Quartzite pebble)
Sedimentary
Red Jasper (possibly)
Jasper (a variety of Chalcedony, SiO2)
Mineral
Green Aventurine
Aventurine Quartz (SiO2 with Fuchsite inclusions)
mineral
Black Tourmaline
Schorl (Na(Fe²⁺)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄)
Mineral
Aventurine (likely Green Aventurine)
Aventurine (a variety of quartz, SiO₂, with common inclusions of fuchsite)
Mineral/Metamorphic Rock
Jasper
Silicon dioxide (SiO2)
sedimentary
Orbicular Jasper
Silicon Dioxide (SiO2), variety of Chalcedony
Mineral
Metal Chain (Likely Steel or a Steel Alloy)
Steel (primarily iron and carbon); specific alloy unknown
Man-made Object (Metal/Alloy)
White Howlite
Howlite (Calcium borosilicate hydroxide, Ca2B5SiO9(OH)5)
mineral
Slate
Slate (a fine-grained, foliated metamorphic rock). Mineral composition: Primarily composed of mica minerals (muscovite, chlorite, sericite) and quartz, with minor amounts of hematite, pyrite, and other accessory minerals.
sedimentary
Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Limonite
Hydrous Iron Oxide (often Goethite FeO(OH), Lepidocrocite γ-FeO(OH), and other amorphous iron oxyhydroxides)
Mineral
Anthracite
Anthracite Coal
sedimentary
Jasper Beach Pebble
Silicon Dioxide (SiO2) - Macro-crystalline Quartz
sedimentary
Blue Goldstone
Aventurine Glass
Man-made glass (often grouped with minerals in lapidary)
Quartz (Milky or White Quartz)
Silicon Dioxide (SiO2)
mineral
Red Jasper
Silicon dioxide (SiO2) with iron oxide (Hematite) inclusions
sedimentary
Howlite
Calcium Borosilicate Hydroxide (Ca2B5SiO9(OH)5)
mineral
Opalite
Synthetic Glass (Hydrated Crystalline Silicon Dioxide simulation)
mineral
Opalite
Synthetic Glass, SiO2 base with metallic inclusions
mineraloid (synthetic)
Smoky Quartz
Quartz (SiO₂)
Mineral
Banded Gneiss (River Rock/Pebble)
Gneiss (specifically a banded variety often found as a river rock)
Metamorphic Rock
Carnelian
Chalcedony (cryptocrystalline quartz), SiO2 (Silicon Dioxide)
mineral
Jasper
Jasper (Silicon Dioxide, SiO2)
sedimentary (microcrystalline quartz)
Green Aventurine
Silicon dioxide (SiO2) with inclusions of Fuchsite mica
metamorphic
Yellow Jasper
Microcrystalline Quartz with Iron Oxide (SiO2)
sedimentary
Yellow Jasper
Silicon Dioxide (SiO2) with impurities of Iron or Goethite
sedimentary
Dyed Crackle Quartz (Green)
Quenching-treated Quartz (Silicon Dioxide, SiO2)
mineral
Unakite
Epidote-Feldspar rock (specifically, a variety of granite)
Metamorphic rock
Black Obsidian with white veins
Volcanic Glass (70–75% SiO2)
igneous
Limonite (with Pyrite)
Limonite (Hydrated Iron Oxide) - FeO(OH)·nH2O
mineral
African Turquoise (Jasper)
Polychrome African Jasper (often marketed as 'African Turquoise' due to its color, but it is not true turquoise)
Rock
Blue Goldstone
Goldstone (artificial glass)
Mineral (man-made glass, not natural)
Limonite with Quartz (Gossan)
Hydrated iron(III) oxide-hydroxide mixture (FeO(OH)·nH2O) with Silicon Dioxide (SiO2)
Mineral
Jasper, possibly Brecciated Jasper or Ocean Jasper due to patterns and color
Silicon Dioxide (SiO2), a variety of Chalcedony
Sedimentary Rock