Heavy metals only mercury, lead and bismuth meet all of them. Despite this lack of agreement, the term (plural or singular) is widely used in science. A density of more than 5 g/cm is sometimes quoted as a commonly used criterion and is used in the body of this article. The earliest known metals—common metals such as iron, copper, and tin, and precious metals such as silver, gold, and platinum—are heavy metals. From 1809 onwards, light metals, such as magnesium, aluminium, and titanium, were discovered, as well as less well-known heavy metals including gallium, thallium, and hafnium. Some heavy metals are either
Federated Moulders' (Metals) Union of Australia the Amalgamated Metals, Foundry and Shipwrights' Union in February 1983. Federated Moulders' (Metals) Union of Australia The Federated Moulders' (Metals) Union of Australia (FMMUA) was an Australian trade union which existed between 1899 and 1983. It represented moulders - skilled tradesmen who fabricated the moulds used to cast metal products in foundries. Despite its exclusive attitude towards membership, which kept the total number of FMMUA members low throughout its existence, the vital position of moulders in major industries such as mining, manufacturing and the railways ensured that the union remained industrially powerful, and the union had a reputation for being