Manufacture of jewelry by casting with preset gems

In the manufacture of an article of jewelry cast in precious metal by a lost wax procedure and having a seat in which a gem is preset, the gem having a girdle and the seat having a sidewall formed with opposing undercut grooves in which portions of the girdle engage as gem retention means, the method comprising the steps of molding a wax model having a seat with a sidewall formed with opposing undercut grooves, the wax model being formed from a wax having a predetermined resiliency enabling flexing of the sidewall of said seat, snapping a gem having said girdle into set position in said seat by application of downward pressure on the gem to resiliently flex said sidewall permitting portions of the girdle to enter into engagement with said opposing undercut grooves, mounting the wax model with the gem set in the seat on a wax tree, embedding the wax tree in investment material in a flask, raising the temperature of the flask by predetermined increments and time intervals to a predetermined temperature to remove the wax and cure the investment material providing a mold cavity with the gem suspended therein, injecting molten precious metal into the mold cavity to form a metal casting in which the girdle of said suspended gem is engaged by undercut grooves of the metal casting, cooling the flask and its contents, and breaking the investment material after the flask and its contents cool to remove the precious metal article with the gem preset in said seat.