Mineral Many sulfide minerals are economically important as metal ores; examples include sphalerite (ZnS), an ore of zinc, galena (PbS), an ore of lead, cinnabar (HgS), an ore of mercury, and molybdenite (MoS, an ore of molybdenum. Pyrite (FeS), is the most commonly occurring sulfide, and can be found in most geological environments. It is not, however, an ore of iron, but can be instead oxidized to produce sulfuric acid. Related to the sulfides are the rare sulfosalts, in which a metallic element is bonded to sulfur and a semimetal such as antimony, arsenic, or bismuth. Like the sulfides, sulfosalts are
Metal detector many scientists and engineers used their growing knowledge of electrical theory in an attempt to devise a machine which would pinpoint metal. The use of such a device to find ore-bearing rocks would give a huge advantage to any miner who employed it. Early machines were crude, used a lot of battery power, and worked only to a very limited degree. In 1874, Parisian inventor Gustave Trouvé developed a hand-held device for locating and extracting metal objects such as bullets from human patients. Inspired by Trouvé, Alexander Graham Bell developed a similar device to attempt to locate a bullet lodged