Specifications
Lead on combining with other elements forms different colourful compounds and pigments which are widely used in different areas
Naples yellow, also called antimony yellow, can range from a somewhat muted, or earthy, reddish yellow pigment to a bright light yellow, and is the chemical compound Lead (II) antimonate. Its chemical composition is Pb(SbO
3)2/Pb
3(Sb
3O
4)
2. It is also known as jaune d'antimoine. It is one of the oldest synthetic pigments, dating from around 1620. The related mineral pigment, bindheimite, dates from the 16th century BC, however this natural version was rarely, if ever, used as a pigment. Naples yellow was used extensively by the Old Masters and well into the 20th century.
Red Lead, also called minium, Leadtetraoxide or triplumbic tetroxide, is a bright red or orange crystalline or amorphous pigment. Its Latin name minium originates from the Minius River in northwest Spain where it was first mined. Natural minium is uncommon, forming only in extreme oxidizing conditions of Lead ore bodies. The best specimens known come from Broken Hill, New South Wales, Australia, where they formed as the result of a mine fire.
The melting point of Lead tetroxide is 500 °C, at which it decomposes to Lead (II) oxide and oxygen.
Chemically Red Lead is Lead tetroxide, Pb
3O
4, or 2PbO.PbO
2. It is used in the manufacture of batteries, Lead glass and rust-proof primer paints. Red Lead is the traditional pigment for rust-inhibiting priming paints applied direct to iron and steel. Calcium plumbate based paints are particularly effective on galvanized steel avoiding the need for etch primers.
White Lead is the chemical compound (PbCO
3)
2Pb(OH)
2. It was formerly used as an ingredient for Lead paint and a cosmetic called Venetian Ceruse, because its opaque quality made it a good pigment. White Lead has been the principal white of classical European oil painting. Historically, white Lead was produced by the Dutch process. White Lead occurs naturally as a mineral, in which context it is known as hydrocerussite. It is used in making paint with good external weathering characteristics.
Lead Chromate (yellow) and Lead Molybdate (red orange) are still used in plastics and to a lesser extent paints. Lead chromate is used extensively as the yellow pigment in road markings.