Scoria
Vesicular Basalt / Scoriaceous Basalt
igneous
Category
Organic (Non Geological)
Browse organic (non geological) specimens identified by the Rock Identifier community.
Carnelian
Chalcedony (cryptocrystalline quartz), SiO2 (Silicon Dioxide)
mineral
Quartz (likely a clear or rock crystal variety)
Quartz (SiO2 - Silicon Dioxide)
Mineral
Carnelian
Carnelian (a variety of Chalcedony, SiO₂)
Mineral
Quartzite
Quartzite (primarily SiO2)
metamorphic
Brown Jasper
Jasper (a cryptocrystalline variety of Quartz, SiO2)
Mineral, specifically a variety of Quartz
Obsidian
Obsidian (volcanic glass)
igneous
Coarse-grained Granite (Quartz and Feldspar dominated)
Granitoid (KAlSi3O8 – NaAlSi3O3 – CaAl2Si2O8 – SiO2)
Igneous
Limonite and Goethite (Ironstone)
Hydrous Iron Oxide Mixture (FeO(OH)·nH2O)
sedimentary
Rutilated Quartz
SiO2 with TiO2 inclusions
Mineral
Red Sandstone (Siltstone/Mudstone variety)
Ferruginous Sandstone (composed primarily of Quartz with Hematite cementation)
sedimentary
Rutilated Quartz
SiO2 with TiO2 inclusions (Quartz with Rutile)
mineral
Carnelian
Carnelian (SiO2 - Silicon Dioxide with Iron Oxide impurities)
mineral
Citrine
Quartz (SiO₂)
Mineral
Jade (Nephrite or Jadeite)
Nephrite (Ca2(Mg,Fe)5Si8O22(OH)2) or Jadeite (Na(Al,Fe3+)Si2O6)
Metamorphic Rock / Mineral
Amethyst
Amethyst is a variety of Quartz (SiO₂)
Mineral
Amethyst
SiO2 (Silicon Dioxide) - a variety of Quartz
Mineral
Ferruginous Quartz
Silicon Dioxide (SiO2) with Hematite (Fe2O3) inclusions
mineral
Quartzite with Chlorite/Epidote
Metamorphosed Quartzite (SiO2)
metamorphic
Pink Granite (Crystalline Granite)
Igneous Intrusive Rock (Felsic Plutonic)
igneous
Red Jasper
Jasper (a variety of Quartz, SiO2)
Mineral
Chalk (Calcitic)
Calcium Carbonate (CaCO3) - Biogenic Sedimentary Rock
sedimentary
Jasper with Pyrite (Gold-colored inclusions)
Silicon Dioxide (SiO2) with Iron Disulfide (FeS2) inclusions
sedimentary (chemical/biological)
Smoky Quartz
Quartz (SiO₂)
Mineral
Snowflake Obsidian (or similar porphyritic volcanic rock)
Obsidian with Spherulites (if glassy), or Porphyritic Rhyolite/Andesite (if crystalline groundmass)
igneous
Black Tourmaline
Schorl (Na(Fe²⁺)₃Al₆(OH)₄(BO₃)₃Si₆O₁₈)
mineral
Flower Agate (Cherry Blossom Agate)
Chalcedony (SiO2) with Opaque Inclusions
mineral
![Limonitic Scoria (Vesicular Basalt with Iron Staining) (Highly vesicular basalt heavily stained by Limonite [FeO(OH)·nH2O]) — igneous](https://media.rockidentification.com/2f0eaf7f-d274-4028-af3e-e31436d83d19-thumbnail.jpg)
Limonitic Scoria (Vesicular Basalt with Iron Staining)
Highly vesicular basalt heavily stained by Limonite [FeO(OH)·nH2O]
igneous
Scoria (Lava Rock)
Mafic extrusive volcanic rock (Scientific formula varies based on mineral content: primarily SiO2, MgO, and FeO)
igneous
Amethyst
SiO2 (Silicon Dioxide)
Mineral
Goldstone (with Tiger's Eye and Quartz)
Aventurine glass (Synthetic SiO2 with Cu inclusions)
mineral
Basalt
Extrusive mafic rock (Basalt)
igneous
Tiger's Eye
Silicon dioxide (SiO2) with fibrous inclusions of crocidolite
Mineral
Green Aventurine (Green Quartz)
Silicon Dioxide (SiO2) with inclusions of Fuchsite (K(Al,Cr)2(AlSi3O10)(OH)2)
Mineral/Metamorphic rock
Carnelian
Carnelian (a variety of Chalcedony, which is a microcrystalline quartz, SiO₂)
Mineral
Serpentine
Serpentine Group Minerals (e.g., Antigorite, Chrysotile, Lizardite)
Mineral, often found as a rock
Basalt
Extrusive mafic igneous rock
igneous
Amethyst
SiO2 (Silicon Dioxide)
Mineral
Amethyst Quartz
SiO2 (Silicon Dioxide)
Mineral
Obsidian
Obsidian (volcanic glass, amorphous silica rich rock)
Igneous
Quartz (various varieties)
SiO₂ (Silicon Dioxide)
Mineral
Granite Cobble
Granite (Phaneritic Quartz-Feldspar Felsic Rock)
igneous