“It never occurs as a free element, but only in ores such as pyrolusite, manganite, psilomelane, and rhodochrosite.”

“As mentioned above, the manganite produced by the present invention may also be air-oxidized to produce manganese dioxide.”

“Museum-quality specimens of manganite have been collected from the Taylor mine for many years and can be seen in collections around the world.”

“In older Glossaries there were listings following both columbite and tantalite that referred the reader to ferrocolumbite, magnocolumbite, manganocolumbite, and so on.”

“Less abundant elements, which are equally necessary for life, include calcium, manganese, iron, and iodine.”

“For example, a typical alkaline battery contains manganese dioxide and zinc, which react to form zinc oxide.”

“Unlike metals such as iron, copper, magnesium, manganese, and nickel, gold has no natural biological role.”