Mahogany Obsidian
Volcanic Glass with Hematite (SiO2 + Fe2O3)
igneous
Category
Mineral Based Alloy (Anthropogenic)
Browse mineral based alloy (anthropogenic) specimens identified by the Rock Identifier community.
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Snowflake Obsidian
Spherulitic Obsidian (Volcanic Glass with Cristobalite inclusions)
igneous
Granite
Phaneritic Felsic Igneous Rock
igneous
Granite
Granite (Felsic Plutonic Rock)
igneous
Limestone (Ocherous)
Calcium Carbonate (CaCO3) with Iron Oxide (Limonite)
sedimentary
Basalt River Cobble
Basalt (Aphanitic Mafic Volcanic Rock)
igneous
Hag Stone
Perforated Sedimentary Rock (typically Limestone or Sandstone)
sedimentary
Basalt with Quartz Vein
Mafic Igneous Rock (SiO2 filling)
igneous
Dalmation Stone (often called Dalmatian Jasper)
Peralkaline Rock (Microgranite/Aplite), SiO2 with inclusions of Arfvedsonite
igneous
Pink Granite
Phaneritic Felsic Intrusive Igneous Rock
igneous
Ferruginous Quartz
Silicon Dioxide (SiO2) with Hematite/Limonite impurities
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Greenshist / Chlorite Schist
Chlorite schist (contains (Mg,Fe)3(Si,Al)4O10(OH)2·(Mg,Fe)3(OH)6)
metamorphic
Granite
Phaneritic plutonic rock (primarily Quartz, Feldspar, and Mica)
igneous
Schist (Biotite/Mica Schist)
Medium-grade regional metamorphic rock (rich in Phyllosilicates)
metamorphic
Red Sandstone
Arenite (with Iron Oxide / Hematite staining)
sedimentary
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic Volcanic Rock)
Igneous
Sandstone (likely Greywacke or Siltstone variety)
Arenite / Siltstone (primarily SiO2)
sedimentary
Muscovite Mica (with Quartz)
Muscovite (KAl2(AlSi3O10)(OH)2)
mineral
Fire Agate
Silicon Dioxide (SiO2) with layered Iron Oxide (Limonite/Goethite)
mineral
Lepidolite
Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2)
mineral
Granodiorite (River Cobble)
Granodiorite (contains Quartz, Plagioclase Feldspar, Biotite Mica)
igneous
Pink Lepidolite
Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2)
mineral
Amethyst on Agate/Host Rock
Silicon Dioxide (SiO2) with iron impurities
mineral
Fire Agate
Silicon Dioxide (SiO2) with layers of Limonite/Goethite
mineral
Labradorite
Labradorite (Plagioclase Feldspar Series - (Ca, Na)(Al, Si)4O8)
mineral
Bloodstone (Heliotrope)
Silicon Dioxide (SiO2) - Variety of Chalcedony/Jasper
mineral
Tree Agate (or Moss Agate)
Dendritic Agate (Silicon Dioxide - SiO2)
mineral
Labradorite
Labradorite (Ca,Na)(Al,Si)4O8
mineral
Diorite Porphyry (Polished Pebble)
Diorite
igneous
Schist
Mica Schist (primarily Muscovite and Quartz)
metamorphic
Aura Quartz (Titanium or Angel Aura coated)
Silicon Dioxide (SiO2) with metallic vapor coating
mineral
Lepidolite
Lepidolite (K(Li,Al)3(Al,Si)4O10(F,OH)2)
mineral
Mica Schist
Schist (Crystalline metamorphic rock)
metamorphic
Quartz with Muscovite Mica
SiO2 with KAl2(AlSi3O10)(OH)2
mineral group
Dalmatian Stone
Dalmatian Jasper (Peralkaline Quartz-Feldspar Rock)
igneous
Quartz / Quartzite Fragment
Silicon Dioxide (SiO2)
igneous, sedimentary, or metamorphic (mineral-based)
Laterite (Iron-rich bauxite or Gossan)
Ferricrete (Fe2O3·nH2O)
sedimentary
River Cobble (Conglomerate context)
Unconsolidated Fluvial Alluvium (comprised of various lithologies like Quartzite, Granite, or Basalt)
sedimentary
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic volcanic rock with secondary mineral fillings)
igneous
Coquina
Biogenic Limestone (Calcite/Aragonite base, CaCO3)
sedimentary