At this point, the processing
of the jewel is done. The finishing operations,
such as burring, burnishing, and polishing are performed
by machines called sieving machines. Even though it
is part of the modern mechanized finishing processes,
sieving is in fact a very ancient procedure, known from
the ancient Egyptians and from the Celts. Our company
has a vast range of finishing machines, among which:
Vibrating sieving machines: the polishing is
done by the constant circular vibrating movement of
the small steel balls submerged in a solution of water
and soap. Rotary sieving machines: the jewel is polished
by balls or other materials which rotate using the centrifugal
force.
Magnetic
sieving machines: the jewel is submerged in
a tank full of metal pins and a solution of water
and soap. On the bottom of the machine, there
is a magnet which rotates, moving the pins; by
their moving, the pins clean and polish the metal.
Centrifugal
sieving machines: they perform burnishing,
prepolishing and polishing operations. This
type of machine operates without water and the
jewel is submerged in different compositions,
generally of natural origins, such as small
wood of different shapes or nut shells treated
more or less finely.
