Cutting calibrated cabochons with Joy 1

This is a slide of rare green quartz 5 mm thick.
1×1 cm size pieces are cut


Heat the stones slowly on a heating plate with an Aluminium plate as a buffer. Fix themonto the dops with wax
Cool the dops in an Aluminium doprack


For cutting 10 mm calibrated cabochons use a 150 mm bronzesitered wheel with a 5 mm quadrant profile. Grit of the wheel is D151.
The gemstone and the masterpreform are clamped onto the precutter

The stone must be perfectly adjusted to the wheel. The watersupply is opened, the machine started and the stone slowly sunk down onto the spinning wheel
The stone is cut to a perfect hemisphere.


Time for pre-cutting a stone is about 1 min.
For finishing the stone is mounted on a handholder


Fine cutting is done by nova disc 600 grit
Polishing is done by felt with Aloxid


Very hard stones can be polished on a STARLAP with diamond polish.
After cutting wax is solved with alcohol


Great result! Calibrated cabochnos 10 mm
Time for cutting and polishing per gemstone about 3-4 min