Feldspar (likely Orthoclase or Plagioclase)
Tectosilicate Feldspar (KAlSi3O8 to (Ca,Na)(Al,Si)4O8)
Category
Browse mineral like byproduct (technogenic) specimens identified by the Rock Identifier community.
Feldspar (likely Orthoclase or Plagioclase)
Tectosilicate Feldspar (KAlSi3O8 to (Ca,Na)(Al,Si)4O8)
Epidote with quartz/feldspar
Epidote, Ca2(Al,Fe)3(SiO4)3(OH)
Yellow Ochre / Limonite
Limonite (FeO(OH)·nH2O)
Limonite (Ironstone)
Hydrated Iron Oxide (FeO(OH)·nH2O)
Quartzite with Mica / Gneiss Pebble
Metamorphic Rock (Quartz-Feldspar-Mica aggregate)
Schist
Mica Schist
Moss Agate
Chalcedony (Silicon Dioxide, SiO2) with inclusions of Chlorite, Manganese, or Iron
Howlite
Calcium borosilicate hydroxide (Ca2B5SiO9(OH)5)
Citrine
SiO2 (Silicon Dioxide)
Yellow Aventurine
Quartz with inclusion minerals (SiO2)
Diamond
Native Carbon (C)
Milky Quartz with Iron Staining
Silicon Dioxide (SiO2)
Bivalve Fossil (Clam)
Class Bivalvia (Mollusca)
Chrysoprase
Silicon dioxide with nickel impurities (SiO2 + Ni)
Milky Quartz with Iron Oxides
Silicon Dioxide (SiO2) with Fe2O3 inclusions
Gneiss (specifically Banded Gneiss)
Gneiss
Greenschist
Chlorite-actinolite schist
Lepidolite in Mica Schist
K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2
Gneiss
Gneiss (High-grade metamorphic rock)
Quartz pebble
Silicon dioxide (SiO2)
Quartz Vein in Basalt or Mafic Rock
Silicon Dioxide (SiO2) vein in volcanic/mafic matrix
Obsidian
Volcanic Glass (SiO2)
Greenschist / Basalt Beach Pebble
Metabasalt / Chlorite Schist
Quartzite
Silicon Dioxide (SiO2)
Pyrite Concretion (Grapestone)
Iron Sulfide (FeS2) Concretion
Amethyst (Tumbled Quarz)
Silicon Dioxide (SiO2) with iron impurities
Sandstone (Ferruginous)
Arenite with Iron Oxides
Septarian Nodule (or Mudstone with Septarian Cracking)
Septarian Concretion (Composition: Calcite, Aragonite, and Limestone/Claystone)
Gneiss
High-grade foliated metamorphic rock
Bauxite
Bauxite (Al2O3·2H2O)
Tourmalinated Quartz
Silicon Dioxide (SiO2) with inclusions of Schorl (NaFe2+3Al6Si6O18(BO3)3(OH)3OH)
Black Obsidian
Obsidian (Volcanic Glass, SiO2 + impurities)
Obsidian
Volcanic Glass (SiO2 + minor impurities)
Gneiss
Gneiss
Petrified Bone Pebble
Silicified Fossilized Bone
Amazonite
Potassium Feldspar (KAlSi3O8)
Amazonite
Amazonite (KAlSi3O8)
Sandstone with Iron Staining
Arenite (SiO2 with Fe-oxide coatings)
Limonite/Goethite on Shale
Hydrous ferric oxides (FeO(OH)·nH2O) often associated with argillaceous rock
Lepidolite
Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2)
Dendritic Opal
Hydrated Silica (SiO2·nH2O) with Manganese or Iron Oxide inclusions
Clear Quartz (Tumbled)
Quartz (Silicon Dioxide - SiO2)