exceptional
zircon, of a beautiful olive-green tint, of the dimensions shown in
Fig. 79, was sold at the auction of M. Dree for the sum of $16. A
diamond of the same dimensions, even if only a rose, would weigh about
5 carats, and would bring not less than $1800.
The
finest specimens of zircon are brought from Ceylon; but they are also
found in Europe, in the vicinity of Lisbon, and in France, near the
town of Puy.
GARNETS.
With
materials which, though different in their nature, are cut and placed
in the same manner, it is possible to construct several edifices
resembling each other in form and disposition.
That which Art accomplishes more or less completely, Nature realizes perfectly.
Out
of substances essentially differing in their nature she constructs
well-defined and crystallized compounds, which appear to all intents
and purposes identical, and yet are not so.
This phenomenon is called in science isomorphism, from the Greek isos, equal; and morphi, form.
It was discovered by the celebrated German chemist Mitscherlich, and
the discovery is considered one of the greatest scientific achievements
of our century.
