An Investigation of the Geological Occurrence and Use of Titanium With Special Reference to the San Gabriel Titanium Deposits, California
<p>It has been customary to class titanium with the rare elements, but in reality it is one of the most abundant of metals. Geochemists have estimated that it constitutes 0.44 per cent of the solid crust of the earth and ranks ninth in relative abundance of the ninety odd elements found there....