meerschaum
Concise Oxford English Dictionary © 2008 Oxford University Press:
meerschaum /ˈmɪəʃɔːm, -ʃəm/
▶noun a soft white clay-like material consisting of hydrated magnesium silicate, found chiefly in Turkey.
■ a tobacco pipe with a bowl made from this.
– origin C18: from Ger., lit. ‘sea-foam’, translation of Pers. kef-i-daryā (alluding to its frothy appearance).
'meerschaum' also found in these Oxford entries:

