Chunk of aluminum, 2.6 grams, 1 x 2 cm. — Photo: Materialscientist · CC Attribution 3.0 Unported
Aluminium
The lightweight silvery metal (symbol Al, atomic number 13) — about a third the density of steel and Earth's most abundant metal.
Intro adapted from Wikipedia (CC BY-SA).
Aluminium is an IMA-recognized mineral species in the native element class, with the chemical formula Al.
It crystallizes in the cubic crystal system (space group Fm3m). It is a member of the Copper structural group.
Key properties: Mohs hardness 2–3; specific gravity 2.707; white streak; Metallic luster.
IMA symbol Al, IMA status: approved, named in 1978.
Found in a gabbro-dolerite massif (Billeekh intrusion, Russia); in aluminum-rich rocks; in high-temperature hydrothermal Sn–W deposits and their alteration zones; in volcanic ash.
It is found associated with Cu, Zn, Sn, Pb, Cd, Fe, Sb, moissanite (Billeekh intrusive, Russia); magnetite, ilmenite, hematite, pyrite, iron (Tolbachik volcano, Russia); Cu, S.
Named aluminum by Humphry Davy, who discovered the element.