18k pendant with diamonds

The sheet of 18k that I am working with is 40mm square and 1mm thick. How do you turn it into a pendant? First I use dividers to find the center of the sheet by scribing a line down the center in both directions. Where they intersect is the center of the sheet. I then use the dividers to scribe a circle.

I use a jewellers saw to carefully cut on the outside of the scribed line turning the square into a circle.

I dip the circle in a mixture of alcohol and Borasic acid to coat it and protect it from coming into contact with oxygen while heating. Yellow gold and platinum don't react when heated but white gold and Sterling silver need to be protected when heated or you get a black coating that appears on your metal.

I then use a propane torch to heat the disc.

This process is called annealing. The heat changes the microstructure of the metal when it reaches 1400 degrees F, or a glowing red. Yellow gold can be quenched in water to cool it but white gold can become brittle and crack if quenched too quickly.
The metal is now nice and soft and ready to hammer and shape into a low dome. I will them anneal the metal a second time before putting on the final hammer finish. There is nothing worse then having a piece crack on you from overworking it.
Next week we are on to hammering!