ossible easily to reproduce the same form over and over
again by splitting, whereas by simply breaking, the form of the crystal
would be lost; just as a rhomb of Iceland spar might be sawn or broken
across the middle and its form lost, although this would really be more
apparent than real, since it would be an alteration in the mass and not
in the shape of each individual crystal. And given further cleavage, by
time or a sudden breaking down, even the mass, as mass, would eventually
become split into smaller but perfect rhombs.

Much skill is, therefore, required in cutting and fashioning a precious
stone, otherwise the gem may be ruined at the onset, for it will only
divide along its lines of cleavage, and any mistake in deciding upon
these, would "break," not "split" the stone, and destroy the beauty of
its crystalline structure. An example of this was specially seen in the
great Cullinan diamond, the splitting of which was perhaps the most
thrilling moment in the history of precious stones.[A] The value of the
enormous crystal was almost beyond computation, but it had a flaw in the
centre, and in order to cut out this flaw it was necessary to divide the
stone into two pieces. The planes of cleavage were worked out, the
diamond was sawn a little, when the operator, acknowledged to be the
greatest living expert, inserted a knife in the saw-mark, and with the
second blow of a steel rod, the marvellous stone parted precisely as
intended, cutting the flaw exactly in two, leaving half of it on the
outside of each divided portion. The slightest miscalculation would have
meant enormous loss, if not ruin, to the stone, but the greatest feat
the world has ever known in the splitting of a priceless diamond was
accomplished successfully by this skilful expert in an Amsterdam
workroom in February, 1908. Some idea of the risk involved may be
gathered from the fact that this stone, the largest ever discovered, in
the rough weighed nearly 3,254 carats, its value being almost anything
one cared to state--incalculable.

[Footnote A: The hammer and knife used in cutting the diamond, the two
largest pieces of which are now called "The Stars of Africa," together
with a model of the great uncut stone, are in the Tower of London
amongst the Regalia.]

These cleavage planes help considerably in the bringing of the stone to
shape, for in a broad sense, a finished cut stone may be said to be in
the form in which its cleavages bring it. Part