icient for all
requirements. Production has come chiefly from Virginia. Additional
quantities have been imported from Canada and Norway. The recently
developed deposits of Pablo Beach, Florida, may produce important
amounts of titanium minerals along with the output of zircon and
monazite.

GEOLOGIC FEATURES

The principal titanium minerals are rutile (titanium oxide) and ilmenite
(iron titanate). These minerals are formed mainly under high
temperatures, either during the original solidification of igneous
rocks, or as constituents of the pegmatites which follow the
crystallization of the main igneous masses. The Virginia production
comes from pegmatite dikes cutting through gabbros, syenites, and
gneisses. The deposits contain rutile in amounts as high as 30 per cent
of the mass, but averaging 4 or 5 per cent, in addition to varying
amounts of ilmenite. Titaniferous magnetites, formed in many basic
igneous rocks by the segregation of certain iron-bearing materials into
irregular masses, contain large quantities of ilmenite which are not
commercially available under present metallurgical processes.

Rutile and ilmenite both have high specific gravity and are little
affected by weathering. Consequently they are not decomposed at the
surface, but when carried away and subjected to the sorting action of
streams and waves, they form placer deposits. Both of these minerals are
recovered from the sands at Pablo Beach, Florida.

MAGNESITE

ECONOMIC FEATURES

The most important use of magnesite is as a refractory material for
lining furnaces and converters. It is also used in the manufacture of
Sorel cement for stucco and flooring, in making paper, in fire-resisting
paint, in heat insulation, and as a source for carbon dioxide. Small
amounts are used in Epsom salts and other chemicals.

As taken from the ground the ore consists principally of the mineral
magnesite or magnesium carbonate, with minor impurities (1 to 12 per
cent) of lime, iron, silica, and alumina. In making magnesite bricks, it
is calcined or "dead-burned" to drive out the carbon dioxide.

Austria-Hungary and Greece are the large European producers of magnesite
and Scotland supplies a little. Most of the European production is
consumed in England and the Central European countries, but part has
been sent to America. Outside the United States there are American
supplies in Canada, and recent developments in Venezuela and Mexico
(Lower California)