Magnesite

摘要

Magnesite is a common stone that may appear in attractive specimens,but most of the time it's aesthetically challenged.Weird,isn't it?rnMost magnesite is formed by the alteration of serpentine.It occurs as veins or pods in serpentine or as crystals embedded in chlorite.rnMagnesite is a major ore of the metal magnesium-the other source is brine-and is the preferred ore for some uses,such as cement or fireproof ceramic.When burnt,magnesite lets carbon dioxide loose and can be used for cement,just like calcite.So-called Sorel cement (or magnesia cement) is based on magnesite,and is hard,non-shrinking,and does not produce dust.It's used for stucco and for floors,particularly in wet rooms.When heated to 1400-1500°C,pure magnesite wiE be 'dead burnt,' containing less than 0.5% carbon dioxide.This is used as a refractory in the metallurgical industry.Hydrated,burnt magnesite dissolved in water is called milk of magnesia,and is an old household remedy for stomach pain,poor digestion,and acidity.