The discovery, or acknowledgment, of bismuth as an element straddles the ancient and modern eras. The heavy metal bismuth was referred to and used by a number of ancient cultures, but was usually thought of as a variety of lead or possibly tin.
Bismuth began to be recognized as a distinctive substance in the late Middle Ages. Alchemists and early mineralogists were paying stricter attention to the properties of things. So, for example, Georgius Agricola mentions bismuth around 1546. Eventually, in the 18th century, bismuth as an element became unmistakable.
Mining and Production
Bismuth ores are more common than gold. 8,500 tonnes were produced in 2014. China was the biggest producer at 7,600 tonnes. Bismuth is also a byproduct of mining lead, copper, and other metals. Lead ore can contain up to 10% as much bismuth as lead. Therefore, refinery production of bismuth is about twice the amount directly mined.
Properties and Uses
Bismuth is a dense brittle metal appearing more whitish than lead. It has relatively few applications, but environmental concerns and regulation (see below) are increasing the demand, and therefore the price.
Bismuth has a low melting point, and it expands when it freezes as water does. These properties make it useful in casting type, filling molds, and similar uses requiring an exact shape.
Bismuth has a clean tech use because it is much less toxic than lead, antimony, and other heavy metals. As a result, in recent years, the metal has become a popular physical replacement for lead. Bismuth is only 14% less dense than lead, and it is an acceptable choice for fishing weights, shot, and bullets. Bismuth's low melting point allows it to substitute for lead in solder. And so, voluntarily and through legislation, the use of bismuth is diminishing the amount of lead contamination in the environment.