of the Indian specimens is a regular octahedron, the Brazilian
are twelve and occasionally six-faced.* Groups of crystals
including both forms sometimes occur, as may be seen in a
specimen of the Dresden collection. The faces or planes
are frequently convex, having been naturally rounded. In
the form of its crystals, the diamond may be confounded with
the white spinel.
Microscopic cavities or fissures exist in many specimens,
which give them a dark color, while others present a stellated
appearance.
Sometimes this gem will burst or split from natural causes,
a singular phenomenon happening with certain glassy stones
of a faint brown tinge. Specimens perfect when taken from
the mines have been known to be lying in fragments the next
morning. It has been suggested that this catastrophe is
occasioned by the vaporization of the water between the laminae, induced by atmospheric heat, but the real cause is a question for speculation.
Supernatural powers have been ascribed to the diamond,
as if its natural properties were not sufficient to constitute it
one of the most remarkable substances in nature. There has
been a difference of opinion about its medicinal qualities —
some believing it was a deadly poison if taken into the stomach, while others have regarded it an antidote to poison. It is
said that the life of Benvenuto Cellini was attempted by one
of his rivals, by administering to him a draught containing, as
was supposed, pulverized diamond, believed to be a virulent
poison, but the danger was averted by the cupidity of the
apothecary, who prepared the deadly beverage by substituting
the beryl, a cheaper gem. The mysterious death of Sir
* The cube form of the diamond and the hard round bort, the latter being
really a twinning of the cube, are peculiar to Brazil. — G. F. Kunz.
