Meerschaum (Ger., sea foam, so called from its lightness and whitish appearance), or Mag-nesite, a hydrous silicate of magnesia, of composition represented by the formula MgO, Si03 + 2HO. It is a mineral of soft earthy texture somewhat resembling chalk, of hardness 2.5, and of variable specific gravity. It is found in Spain and several countries at the head of the Mediterranean, occurring in the form of veins in serpentine, and also in tertiary deposits. Dr. J. Lawrence Smith found it in Asia Minor in alluvium, apparently the result of the decomposition of carbonate of magnesia belonging to neighboring serpentine rocks. It is largely collected there for the manufacture of pipes and cigar tubes, the town of Konieh furnishing the principal supplies. It is roughly shaped into blocks, or sometimes into rude forms of pipes, for exportation, and freed as far as practicable from the associated minerals, which impair its quality by interfering with the carving and smoothing of its surface. It is fashioned into finished pipes, which are often highly ornamented, in different cities of Europe. Pesth and Vienna are famous for this manufacture.

To produce the yellow and brown colors, which are much admired in the pipes, and which are brought out only after long smoking, the blocks are kept for some time in a mixture of wax and fatty matters. A portion of these is absorbed, and, being subsequently acted upon by the heat and the tobacco fumes, assumes various shades of color. The lightest qualities are too porous for producing the best pipes; and the heaviest are rejected from suspicion of their being artificial products. These artificial preparations are from the parings of the genuine material, which, being reduced to line powder, are boiled in water and moulded into blocks, sometimes with the addition of clay. After drying and contracting, they are ready for carving. This kind is known by the name of Massakopfe or massa bowls. The artificial meerschaums cannot easily be distinguished from the real; but they are generally heavier, and are more free from blemishes, some of which, arising from the presence of foreign minerals, are often seen in the genuine meerschaums.