Meerschaum is opaque and off white, grey or cream color, breaking with a conchoidal or fine earthy fracture, and occasionally fibrous in texture. Because it can be readily scratched with the nail, its hardness is placed at about 2. The specific gravity varies from 0.988 to 1.279, but the porosity of the mineral may lead to error. Meerschaum is a hydrous magnesium silicate with the formula H4Mg2Si3O10.
Most of the meerschaum of commerce is obtained from Asia Minor, chiefly from the plain of Eskişehir in Turkey, between Istanbul and Ankara, where it occurs in irregular nodular masses, in alluvial deposits, which are extensively worked for its extraction. It is said that in this district there are 4000 shafts leading to horizontal galleries for extraction of the meerschaum. The principal workings are at Sepetçi Ocağı and Kemikçi Ocağı, about 20 miles southeast of Eskişehir. The mineral is associated with magnesite (magnesium carbonate), the primitive source of both minerals being a serpentine.
When first extracted meerschaum is soft, but it hardens on exposure to solar heat or when dried in a warm room. Meerschaum is found also, though less abundantly, in Greece, as at Thebes, and in the islands of Euboea and Samos; it occurs also in serpentine at Hrubschitz near Kromau in Moravia. It is found to a limited extent at certain localities in France and Spain, and is known in Morocco. In the United States it occurs in serpentine in Pennsylvania (as at Nottingham, Chester County) and in South Carolina and Utah.
Meerschaum has occasionally been used as a substitute for soapstone, fuller's earth, and as a building material; but its chief use is for smoking pipes and cigarette holders. When smoked, Meerschaum pipes gradually change color, and old Meerschaums will turn incremental shades of yellow, orange, and red from the base on up. When prepared for use as a pipe, the natural nodules are first scraped to remove the red earthy matrix, then dried, again scraped and polished with wax. The rudely shaped masses thus prepared are turned and carved, smoothed with glass-paper and Dutch rushes, heated in wax or stearine, and finally polished with bone-ash, etc.
Meerschaum products traditionally were made in manufacturing centres such as Vienna. Since the 1970s, though, Turkey has banned the exportation of meerschaum nodules, trying to set up a local meerschaum industry. The once famous manufacturers have therefore disappeared. Nowadays, meerschaum pipes not obtained from Turkish producers are usually made of pressed meerschaum or African meerschaum, which are inferior in quality.
Imitations are made in plaster of Paris and other preparations.