Dating in mn
Michele Mercati called magnesia negra manganesa, and finally the metal isolated from it became known as manganese (German: Mangan).
The name magnesia eventually was then used to refer only to the white magnesia alba (magnesium oxide), which provided the name magnesium for the free element when it was isolated much later.
Neither this mineral nor elemental manganese is magnetic.
In the 16th century, manganese dioxide was called manganesum (note the two Ns instead of one) by glassmakers, possibly as a corruption and concatenation of two words, since alchemists and glassmakers eventually had to differentiate a magnesia negra (the black ore) from magnesia alba (a white ore, also from Magnesia, also useful in glassmaking).
The cave paintings in Gargas that are 30,000 to 24,000 years old contain manganese pigments.The primary decay mode before the most abundant stable isotope, Manganese isotopic contents are typically combined with chromium isotopic contents and have found application in isotope geology and radiometric dating.