This necklace contains Charles & Colvard created moissanite. It has been mistakenly pulled and a few links have broken. Repairing the links using pulse-arc-welding technology removes the potential to freeze links, reduces the build-up of oxidation and decreases time required for clean-up as opposed to using a torch for the repair.
Tack-, fusion- and pulse-arc equipment settings will differ and are based upon the volume, amount of contact and alloy of the material you are working with. Practicing using like materials will give you a parameter for the settings required for your application. Keep a record of settings and tasks for future reference.