Cast
iron, though it contracts later in cooling, expands when it solidifies
and the expansion of this liquid interior within the rigid shell, as
it solidified, produced an enormous pressure. When the iron was eaten
away by repeated acid baths, there remained a number of crystals,
microscopic, but veritable diamonds; the carbon had crystallized. The
largest crystals he obtained, however, did not exceed 1/2 millimeter in
diameter. Of all the numerous experiments made so far, if others have
resulted in crystals or crystalline masses which were apparently either
diamond or something very like it, unquestionably genuine diamonds
have been produced by this method only, though I. Friedlander
demonstrated, it is said, that graphite is soluble in fused olivine,
and that it separates out as diamond on cooling.
Electric
sparks passed through a vacuum with a carbon cylinder and a platinum
wire as terminals, for over a month, coated the wire with microscopic
octahedra which were said to scratch corundum. A crystalline mass
containing ninety-seven per cent, carbon was obtained by placing
lithium, paraffin and a little sperm oil in a sealed wrought-iron
cylinder and subjecting it to a very high temperature.
While
scientists at a cost of much time, labor and money, have patiently
studied and experimented, in the effort to crystallize carbon,
charlatans and rascals have been busy deceiving the gullible. Not many
years ago a dealer in imitation gems was very successful in selling
glass diamonds by adopting the idea of gold-plated jewelry. He
announced with a great show of frankness, that his diamonds were not
diamond throughout, but that a piece of very fine crystal glass was
used for
