Goethite
Goethite (α-FeO(OH))
Category
Browse mineral composite specimens identified by the Rock Identifier community.
Goethite
Goethite (α-FeO(OH))
Druzzy Quartz on Matrix
Silicon Dioxide (SiO2)
Prehnite
Prehnite - Ca2Al(AlSi3O10)(OH)2
Sandstone
Arenite (primarily SiO2)
Diorite (Salt and Pepper Rock)
Diorite
Diorite
Diorite (Intermediate intrusive igneous rock)
Gneiss (Stream-worn Cobble)
Gneiss (Metamorphic rock composed primarily of Quartz, Feldspar, and Mica)
Charoite
Charoite (Hydrated potassium sodium calcium barium strontium silicate hydroxyfluoride)
Gneiss (Metamorphic Rock)
Gneiss (high-grade regional metamorphic rock)
Diorite (with Salt-and-Pepper Texture)
Diorite (Intrusive Igneous Rock)
Granite
Granitoid
Red Moss Agate (Jasper)
Silicon Dioxide (SiO2) with Iron Oxide inclusions
Sandstone with Manganese Dendrites/Oxide coatings
Arenite with Pyrolusite and Romanechite (MnO2)
Quartz (Pale Rose or Milky Variety)
Silicon Dioxide (SiO2)
Sandstone (likely Ferruginous)
Arenite (SiO2 with iron oxide impurities)
Gold Nugget
Native Gold (Au)
Granite (with Quartz and Mica)
Phaneritic Felsic Igneous Rock
Fossilized Coral
Anthozoa (Fossilized)
Mica Schist
Muscovite/Biotite Schist
Peacock Ore
Bornite (Cu5FeS4)
Blue Sapphire
Corundum (Al2O3 - Aluminum Oxide)
Mica Schist
Mica Schist (primarily Muscovite or Biotite sheet silicates)
Serpentinite
Serpentinite (composed primarily of mineral group (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4)
Quartzite with Gneissic Banding
Quartzite (primarily SiO2) with mafic mineral inclusions
Oolite (Ooids)
Oolitic Limestone (Principal mineral: Calcite, CaCO3)
Chert (containing Calcite or Quartz inclusions)
Silicon Dioxide (SiO2) with varying mineral impurities
Quartzite
Quartzite (Primary mineral: Silicon Dioxide, SiO2)
Quartzite
Quartzite (Primary mineral: Silicon Dioxide, SiO2)
Onyx Marble (also commonly called Onyx)
Calcite (CaCO3), often with other mineral impurities
Porphyritic Basalt or Diabase with Plagioclase Phenocrysts
Porphyritic Basalt or Diabase; Mineral: Plagioclase Feldspar
Oolite or Oolitic Limestone
Oolitic Limestone (Principal mineral: Calcite, CaCO3)
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic volcanic rock)
Magnetite (Lodestone)
Magnetite (Fe3O4)
Snowflake Obsidian
Vitreous volcanic silicate (SiO2 with Cristobalite inclusions)
Ferruginous Sandstone
Clastic sedimentary rock (SiO2 with Fe2O3/FeO(OH) cement)
Gneiss
Gneiss
Chert (Nodule)
Chert (composed of Microcrystalline Silica/SiO2)
Ironstone Concretion (Moqui Marble Type)
Goethite/Hematite-cemented Sandstone Concretion
Sandstone (Ferruginous)
Arenite (composed primarily of SiO2 with Fe2O3 cement)
Quartzite (River Stone)
Quartzite (composed primarily of Silicon Dioxide, SiO2)
Biological Bone (Patella/Knee)
Patella (part of the Human Skeletal System)
Quartzite Pebble
Metamorphosed Quartz Sandstone (SiO2)