The average typing speed is 38-40 words per minute (wpm) for adults  in a professional working environment (despite many incorrect  reports on the web that it is 50-60 wpm).
Chronic Health Effects The following chronic (long-term) health effects can occur at some time after exposure to Mica and can last for months or years: Cancer Hazard * Some Silicas have been shown to cause cancer in animals. The risk of cancer in humans from Mica is unclear at this time.
Interesting Facts. Biotite mica is sometimes called iron mica because it is more iron-rich than phlogopite. It is also sometimes called black mica as opposed to white mica (muscovite) â both form in some rocks, in some instances side-by-side. Biotite has radioactive elements in it that age used to figure out how old the mineral is.