Calcium's conductivity also holds up better against heating. It is easily shaped and molded, machined, extruded into wire, pressed, and hammered. As would be expected of a highland element, calcium is lightweight, roughly half the density of aluminum. However, calcium is not a good construction material because it is not strong. In fact, calcium is sometimes used to deoxidize some metal surfaces.
Titanium is used for military aircraft and missiles.
Note that it's not a silicate. Ilmenite grains of high purity make up more than one fifth of the Apollo 17 mare samples, on average. Dupont Corp., for example, has used ilmenite ores on a commercial basis and the United States Bureau of Mines has recently reviewed the feasibility of replacing imported rutile with domestic ilmenite as a source for U.S. titanium. Ilmenite minerals also trap solar wind hydrogen very well, so that processing of ilmenite will also produce hydrogen, a rare element on the Moon. Ilmenite was found in significant quantities on the surface of two of the five Apollo lowland sites.