Alumina is a fairly chemically inert and white chemical compound of aluminium and
oxygen with the chemical formula Al2O3. It is the most commonly occurring of several
aluminium oxides, and specifically identified as aluminium(III) oxide. It may also
be called aloxide, aloxite, or alundum depending on particular forms or applications.
Used as filler in plastic and cosmetics, as a catalyst. Corundum used as an abrasive
is considered and industrial mineral.
Aluminium is a chemical element in the boron group with symbol Al and atomic number
13. It is a silvery white, soft, ductile metal. Aluminium is the third most abundant
element (after oxygen and silicon), and the most abundant metal in the Earth's crust.
It makes up about 8% by weight of the Earth's solid surface. Aluminium metal is so
chemically reactive that native specimens are rare and limited to extreme reducing
environments. Instead, it is found combined in over 270 different minerals.The chief
ore of aluminium is bauxite.
Aluminosilicate minerals are minerals composed of aluminium, silicon, and oxygen,
plus countercations. They are a major component of kaolin and other clay minerals.Andalusite,
kyanite, and sillimanite are naturally occurring aluminosilicate minerals that have
the composition Al2SiO5
Amber is fossilized tree resin (not sap), which has been appreciated for its color
and natural beauty since Neolithic times. Much valued from antiquity to the present
as a gemstone, amber is made into a variety of decorative objects. Amber is used as
an ingredient in perfumes, as a healing agent in folk medicine, and as jewelry.