HE
Zircon is a lovely stone, the red and brown varieties being especially
noteworthy. Some of the finest Jargoons present yellow, green, and blue
tints, not unlike those of the Tourmaline, but with much more fire and
lustre. Some specimens when submitted to great heat, increase in
lustre, but at same time lose colour.
The
Zircon is distinguished when in its natural form, by its quadrilateral
crystals, terminating at both ends in a pyramid. It is of adamantine
lustre, transparent to sub-translucent. In former times this gem was
more highly valued than at present.
Although
the localities which yield Zircons fit for working into ornamental
stones are but few, it should be borne in mind that the coarser forms
of Zircon are present in a great variety of rocks, such as the
Zircon-syenite of Norway and Siberia.
Nicols
writing of Zircons 230 years ago, says— "They are found in Ethiopia,
India, and Arabia. The Arabs distinguish three kinds—1, Rubri Coloris :
2, Citrini Coloris : 3, Antimonii Coloris. Of these the worst is found
in the river Iser, which is upon the confines of Silesia and Bohemia."
Klaproth in 1789 discovered in the Zircon an earthy basis, to which he gave the name of Zirconia. It is the
