HOW TO MAKE SYNTHETIC DIAMONDS
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diamond at the beginning. It could not be certain, therefore, whether
the gem we took out was newly formed or the one that we had put in.
More likely it was newly formed since the experiment was repeated a
number of times afterwards and in none were any diamonds found.
Probably the diamond that was put in at the beginning of each
experiment was burned into carbon dioxide by the high temperature of
the furnace.
An
ice-brine solution has been used in most of the experiments to cool
the hot molten mass taken from the furnace, but various other methods
of cooling have been tried. In several experiments, all of which
failed, the fused mass was allowed to cool slowly to room temperature.
It appears that rapid cooling is necessary in order to form diamonds.
In an attempt to secure more rapid cooling, liquid nitrogen and solid
carbon dioxide were used. Neither was satisfactory. The instant hot
molten iron was dropped into liquid nitrogen, the nitrogen changed to
a gas, immediately forming an insulating atmosphere around the iron
which prevented rapid cooling. When solid carbon dioxide was used, it
was impossible to secure a surface contact which would cool the iron
effectively.
When
the white hot fused mass is thrown into the cold water (ice brine
solution), some of the water burns and sometimes explodes since part of
the water decomposes into hydrogen and oxygen. The stone jars that were
first used for holding the cold water were usually broken when the hot
fused mass was thrown into them. Recently large graphite crucibles have
been used.
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