Gneiss
Gneiss
Category
Browse mineral (native element alloy) specimens identified by the Rock Identifier community.
Gneiss
Gneiss
Concrete with Aggregate
Artificial Conglomerate (Cement and Aggregate)
Gneiss (Banded Gneiss)
Gneiss
Silicon Carbide (Carborundum)
Silicon Carbide, SiC
Tumbled rose quartz
Quartz (SiO₂), pink variety
Mixed Mineral and Fossil Collection
Multi-specimen assemblage (SiO2, CaCO3, FeS2, etc.)
Agate
Chalcedony (SiO2)
Limonite with Pyrite
Hydrated Iron Oxide Hydroxide, FeO(OH)·nH2O
Limonite
FeO(OH)·nH2O
Amethyst
Amethyst (Silicon Dioxide, SiO2 with Iron impurities)
Blue Apatite
Apatite (Ca5(PO4)3(F,Cl,OH))
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
Fluorite
Calcium fluoride (CaF2)
Malachite and Azurite on Gossan (Ironstone Matrix)
Cu2CO3(OH)2 (Malachite) on FeO(OH)·nH2O (Limonite/Gossan)
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Blue Calcite
Calcium Carbonate (CaCO3)
Peacock Ore
Bornite (Cu5FeS4) or iridescent Chalcopyrite (CuFeS2)
Vesicular basalt (likely weathered lava rock)
Vesicular basalt; primarily plagioclase feldspar, pyroxene, and volcanic glass, with possible iron-oxide alteration
Fossilized Shark Tooth
Chondrichthyes (class)
Fossilized Shark Tooth (Megalodon or Carcharocles species fragment)
Otodus megalodon / Carcharocles spp. (Apatite / Calcium Phosphate)
Weathered, quartz-rich metamorphic rock (likely schist or gneiss)
Quartz–feldspar–mica schist/gneiss, with surface lichens and iron-oxide staining
Banded Sandstone (Beach Pebble)
Quartz Arenite Sandstone
Proustite
Proustite (Ag3AsS3)
Milky Quartz
Quartz (Silicon Dioxide - SiO2)
Titanium Aura Quartz
Titanium-coated Silicon Dioxide (SiO2)
Limonite with Quartz
Hydrated Iron Oxide Hydroxide, FeO(OH)·nH₂O with SiO₂
Snowflake Obsidian
Obsidian with Cristobalite inclusions
Limonite (Iron Ore)
FeO(OH)·nH2O
Sandstone with Iron Concretion
Arenite with Limonite/Goethite Concretion
Red Sandstone (Iron-stained)
Clastic sedimentary rock (primarily Quartz with Iron Oxides)
Turquoise
Hydrated phosphate of copper and aluminium - CuAl6(PO4)4(OH)8·4H2O
Fluorite
Calcium Fluoride (CaF2)
Limonite
FeO(OH)·nH2O
Selenite (variety of Gypsum)
Calcium sulfate dihydrate (CaSO4·2H2O)
Orange Sapphire
Corundum (Al2O3 with trace elements)
Limonite Geode / Ironstone Nodule
Hydrated Iron Oxide Hydroxide (FeO(OH)·nH2O)
Azurite Malachite (Mixed)
Azurite-Malachite; Azurite: Cu3(CO3)2(OH)2 / Malachite: Cu2CO3(OH)2
Greenstone / Metabasalt
Chlorite schist or Epidiorite
Greenstone
Protolith: Basaltic rock
Greenstone
Greenschist / Meta-basalt
Milky Quartz with Mineral Inclusions
Quartz (Silicon Dioxide, SiO2)