Titanium
Titanium, as a metal, is a heavy, gray, iron-like powder, which is chiefly useful as an alloy with iron, giving it toughness, and preventing bubbles and cracks in casting. It is not as rare as some other metals which have found a wider use.
[Rutile]
TiO₂
[Pl. 28]
Occurs in tetragonal crystals, and in grains; hardness 6.5; specific gravity 4.2; color red to reddish-brown; streak yellowish-brown; luster metallic to adamantine; translucent on thin edges.
Rutile usually occurs in crystals, which are either short and stout, or in needle-like crystals. Twinning is common. In form and general appearance it resembles cassiterite, but the reddish color, and the yellowish-brown streak will distinguish the rutile. It is found in similar rocks, granites, gneisses, syenites, and mica-schists, the two minerals cassiterite and rutile often occurring together. This is also true of the grains, which have been weathered out and are found in sands and gravels of placer deposits. It is found in small quantities in all the New England States, New York, and all down the Appalachian Mountains, especially at Graves Mountain, Ga., and in Arkansas and Alaska.
[Ilmenite]
FeTiO₃
Occurs in granular masses, as black sand, or as tabular hexagonal crystals; hardness 5-6; specific gravity 4.7; color black; streak brownish-red to black; luster metallic; opaque on thin edges.
When ilmenite occurs in crystals they are tabular and resemble hematite in its darker varieties, but the streak readily distinguishes the two. In masses it looks like magnetite, but the lack of magnetism serves to distinguish these two minerals. It is very likely to be associated with cassiterite, rutile, or magnetite in grains which have weathered out of the original rock, and have resisted solution and wear. Sands with a large amount of the above mentioned minerals are termed “black sands,” some of which are important for one or another of these minerals.
Ilmenite is a mineral formed at high temperatures, and probably often deposited from hot vapors. It is found in granites, syenites, and gneisses. Among the better known localities are Orange, N. Y., Litchfield, Conn., Florida, California, etc.