The Collaborative International Dictionary of English v.0.48:

Keilhauite \Keil"hau*ite\ (k[imac]l"hou*[imac]t), n. (Min.)
   A mineral of a brownish black color, related to titanite in
   form. It consists chiefly of silica, titanium dioxide, lime,
   and yttria.
   [1913 Webster]