Gray metal which readily oxidizes forming a brown colored oxide. m.p. 1244±3 ºC; 2271±5.5 ºF b.p. 1962 ºC; 3564 ºF density 7.21 to 7.44 g/cc; 450.1 to 464.5 pound/cubic foot, , depending on allotropic form	memory peg
	1774 Johan Gottlieb Gahn, Sweden
	Μαγνησια (Magnisia), region in Thessaly (Greece) named by Carl Wilhelm Scheele in 1774

Manganese compounds were already used in the Antiquity, but it is difficult to determine the beginning of its usage, once they were mistaken by other compounds such as those of iron and of other elements. Its dioxide, magnesia nigra (MnO₂), was the mineral pyrolusite, sometimes also called simply magnesia or manganese. This term was used in contrast with magnesia alba (hydrated magnesium carbonate, see Magnesium).

The Prussian chemist Johann Heinrich Pott (1692-1777) in 1740, proved that pyrolusite does not contain iron, as it was believed until then, and that it produced a wide variety of salts, which were different from those obtained from the iron oxides.

In 1770 Torbern Olof Bergman (1735-1784), professor of chemistry at Uppsala, distinguished pyrolusite from lime and magnesia alba, described it as the calx of a new metal, but failed to reduce the ore. In 1774 a friend of Bergman, Carl Wilhelm Scheele competed a three year investigation, called it Manganese, and described it as the calx of a metal different from any then known. Bergman's assistant, Johan Gottlieb Gahn (1745-1818), finally isolated Manganese as an element.

Several webpages mention that the metal was discovered in 1770 by Ignatius Gottfred Kaim in Vienna, and that it later was investigated by Bergman and Scheele.

The word Manganese is Italian and probably corrupted from "magnesia." The names magnesia alba and magnesia nigra are derived from Magnesia, Μαγνησια, a prefecture in Thessaly (Greece), with the capital Volos) (see map to the left). Manganese and Magnesium were abundant in oxide and carbonate ores in this region, and they therefore became referred as Μαγνητις λιθος, or stones from Magnesia. The region also contained large amounts of iron oxides (magnetite, or lodestone, for example) so that the ores were magnetized. That explains why magnesium as well as magnet (and magnetism) are derived from Magnesia.
Other sources give a town named Magnesia in Asia Minor as origin, which is incorrect. There were actually two towns named Magnesia in that region, Magnesia ad Maeandrum near Ephesus (abandoned after the Roman times) and Magnesia ad Sipylum near Smyrna (nowadays Manisa).

• Mary Elvira Weeks, Discovery of the Elements, comp. rev. by Heny M. Leicester (Easton, Pa.: Journal of Chemical Education, 1968), pp. 163-169.
• Carl Wilhelm Scheele, excerpts from "On Manganese and its Properties". Kong. Vetenskaps Academiens Handlingar 35, 89, 93, 94, 105-110 (1774) ["Om Brunsten, eller Magnesia, och dess Egenskaper", as excerpted and translated in Alembic Club Reprint #13, The Early History of Chlorine]. (on-line).
• Roland Mathieu, Magnetism of manganites, semiconductors and spin glasses. Dissertation Uppsala University, 2002 (PDF-file on-line).