The Collaborative International Dictionary
Keilhauite
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.
Wiktionary
keilhauite
n. (context mineralogy English) yttrotitanite
Wikipedia
Keilhauite
Keilhauite (also known as yttrotitanite) is a variety of the mineral titanite of a brownish black color, related to titanite in form. It consists chiefly of silicon dioxide, titanium dioxide, calcium oxide, and yttrium oxide.
Keilhauite has a chemical formula of (CaTi,Al,Fe,Y)SiO. It differs from titanite only in that calcium is substituted by up to 12 percent (Y,Ce)O.