Zincite: Red
Oxide of Zinc Oxygen 20%, Zinc 80%. Occurs usually in foliated masses
or in coarse particles or grains, deep red or orange-yellow in color.
It is mined extensively with Franklinite and Willemite and other zinc
ores, at Sterling Hill and Franklin, New Jersey, as a source of zinc.
It forms hexagonal crystals in the zinc furnaces at Bethlehem,
Pennsylvania.
Zinkenite: Sulphide
of Antimony and Lead. Sulphur 22%, Lead 36%, Antimony 42%. Occurs in
crystals, and in columnar, fibrous masses. Color and streak steel-gray.
This mineral occurs in the Harz; in Baden; in France; and also in
the antimony mines of Servier County, Arkansas. It is mined as a
source of Antimony
Zinnwaldite: Lithium-Iron Mica. A monoclinic variety of Lepi-
dolite, containing Lithium :and Iron, occurring in
various forms, fan-shaped groups of crystals, and in
rosettes. It has a pearly luster, is of many colors particularly violet,
gray, yellow, brown and dark green, and is strongly pleochroic.
Occurs in Zinnwald, Saxony; Cornwall, England; in Siberia and Greenland.
Zircon:
Silicate of Zirconium. Silica 32.8%, Zirconia 67.2% A little iron is
usually present. This mineral is the only ore of the rare element
Zirconium. It occurs mainly in crystals and as gravel, opaque or
transparent, varying in tint from colorless, through yellowish-brown to
reddish-brown. Transparent orange-brown or reddish varieties are
sometimes used as gem stones since they possess a high index of
refraction and consequently have a great deal of "fire." These are
called "Hyacinth" by the jewelers.
Zirconium: A
comparatively rare metal which is employed in the manufacture of gauze
used in incandescent gas lights, and in the manufacture of cylinders
for use in procuring
a light from oxyhydrogen jets. It is extracted from the mineral Zircon.
Zoisite:
A mineral of the Epidote group, occurring in deeply striated rhomboid
prisms, much compressed and rounded. Color gray, yellowish or
bluish-gray; brown, grayish-yellow or
reddish-white. A rose-red variety is known as Thulite, and is found
in Norway. It occurs also in the copper mines at Ducktown,
Tennessee.
