Goethite
Goethite (FeO(OH))
Category
Browse minerals specimens identified by the Rock Identifier community.
Goethite
Goethite (FeO(OH))
Chert (with Limestone and Iron Oxide staining)
Cryptocrystalline Quartz (SiO2)
Carnelian Agate
Silicon Dioxide (SiO2) - variety of Chalcedony
Yellow Jasper
Silicon Dioxide (SiO2) with Goethite/Iron inclusions
Chert (Jasper)
Microcrystalline Quartz (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Glauconite (Green Sandstone)
Glauconite (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2
Petrified Wood
Silicified Wood (SiO2)
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of Titanium, Iron, or Manganese
Hematite
Iron(III) oxide (Fe2O3)
Limestone (likely Tufa or Travertine)
Calcium Carbonate (CaCO3)
Quartz (Milky or Iron-stained)
Silicon Dioxide (SiO2)
Fossil Shark Tooth
Selachimorpha (Chondrichthyes dental fossil)
Sulfur (in host rock)
Native Sulfur (S8)
Schist
Mica Schist
Chrysocolla
Chrysocolla (Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O)
Gneiss
Gneiss (High-grade Metamorphic Rock)
Desert Rose
Gypsum (variety Selenite) or Barite: CaSO4 · 2H2O
Banded Gneiss
Gneiss (High-grade regional metamorphic rock)
Snowflake Obsidian
Obsidian with Cristobalite inclusions (SiO2)
Fossilized Shark Tooth (Otodus obliquus)
Otodus obliquus (composed primarily of Fluorapatite)
Geode (unopened)
Chert / Chalcedony Geode (SiO2)
Limonite (Iron Ore)
Limonite (FeO(OH)·nH2O)
Green Jasper
Silicon Dioxide (SiO2) with mineral inclusions
Limonite (Yellow Ochre)
Limonite (Hydrated iron(III) oxide-hydroxide, FeO(OH)·nH2O)
Lepidolite
Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2)
Green Aventurine
Silicon Dioxide (SiO2) with inclusions of Fuchsite mica
Green Sandstone
Glauconitic Sandstone
Granite
Granite (composed primarily of Quartz SiO2, Alkali Feldspar, and Plagioclase Feldspar)
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic volcanic rock)
Gneiss
Gneiss (High-grade Metamorphic Rock)
Turquoise
CuAl6(PO4)4(OH)8·4H2O (Hydrous phosphate of copper and aluminium)
Quartz with Iron Staining
Silicon Dioxide (SiO2) with Limonite/Hematite inclusions
Fuchsite (Chrome Mica)
K(Al,Cr)2(AlSi3O10)(OH)2
Copper Ore with Chrysocolla and Azurite
Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O (Chrysocolla) / Cu3(CO3)2(OH)2 (Azurite)
Magnetite (potentially Hematite)
Magnetite (Fe₃O₄)
Sandstone (Ferruginous)
Arenite (primarily SiO2 with iron oxide Fe2O3 cement)
Quartz Vein in Sandstone
Hydrothermal Quartz (SiO2) in Arenite
Gneiss
Gneiss
Granite Pebbles
Granite (composed primarily of Quartz SiO2, Feldspar (KAlSi3O8 – NaAlSi3O8 – CaAl2Si2O8), and Mica)
Smoky Quartz
Quartz (Silicon Dioxide), Formula: SiO2
Pink Lepidolite
Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2)