asbestus

Amphibole \Am"phi*bole\ ([a^]m"f[i^]*b[=o]l), n. [Gr.
   'amfi`bolos doubtful, equivocal, fr. 'amfiba`llein to throw
   round, to doubt: cf. F. amphibole. Ha["u]y so named the genus
   from the great variety of color and composition assumed by
   the mineral.] (Min.)
   A common mineral embracing many varieties varying in color
   and in composition. It occurs in monoclinic crystals; also
   massive, generally with fibrous or columnar structure. The
   color varies from white to gray, green, brown, and black. It
   is a silicate of magnesium and calcium, with usually
   aluminium and iron. Some common varieties are {tremolite},
   {actinolite}, {asbestus}, {edenite}, {hornblende} (the last
   name being also used as a general term for the whole
   species). Amphibole is a constituent of many crystalline
   rocks, as syenite, diorite, most varieties of trachyte, etc.
   See {Hornblende}.
   [1913 Webster]
    

Asbestus \As*bes"tus\, Asbestos \As*bes"tos\ (?; 277), n. [L.
   asbestos (NL. asbestus) a kind of mineral unaffected by fire,
   Gr. ? (prop. an adj.) inextinguishable; 'a priv. + ? to
   extinguish.] (Min.)
   A variety of amphibole or of pyroxene, occurring in long and
   delicate fibers, or in fibrous masses or seams, usually of a
   white, gray, or green-gray color. The name is also given to a
   similar variety of serpentine.
   [1913 Webster]

   Note: The finer varieties have been wrought into gloves and
         cloth which are incombustible. The cloth was formerly
         used as a shroud for dead bodies, and has been
         recommended for firemen's clothes. Asbestus in also
         employed in the manufacture of iron safes, for
         fireproof roofing, and for lampwicks. Some varieties
         are called amianthus. --Dana.