Jewelry casting is an art form that has been in existence for thousands of years. Since the time that man attained the ability to melt metal, artisans have been pouring molten gold into cavities shaped in stone, plaster, sand, and cuttlefish bone. The solidified castings were then pried, or broken free from the encasements in which they were poured by primitive craftsman who then tooled them into items of adornment.

With the emergence of high-frequency casting A melting and many other technologies, jewelry casting is more vibrant than ever before. Most jewelry casting is completed through the wax loss process, where models created through wax carving, growth, or printing are encapsulated in a gypsum like medium called investment molds. Heat the embedded material to extreme temperature to incinerate the material, creating the impression of the desired shape. Then fill the complex cavity with melted precious metal
The procedures for gold casting and platinum casting are very different. Platinum melts at extreme temperatures and requires specialized skills, equipment, and investment in gypsum. Due to the inclusion of multiple carats and colors in gold castings, the alloy combination determines that each alloy has a unique temperature cycle and process unique to the metal.

Wax models or resin type materials are connected to one another on a sprue to form a tree-like configuration. The alignment of the models is arranged to allow gold or platinum to flow through the “tree” with minimum turbulence or resistance. The “tree” is then suspended inside a metal flask and filled with plaster slurry. Once filled, air bubbles and pockets are removed from the slurry by “debubblizing” the flask inside a bell jar with negative atmosphere.

After hardening and curing, flasks containing invested models are placed in specialized ovens, where the wax is incinerated at temperatures as high as 1600° F for 12-16 hours. A properly burned out flask will have no remaining residue of wax or resin, leaving behind a hollow impression left by the tree and sculptures that were burned from it.

Centrifugal jewelry casting uses the force of a centrifuge to create the inertia necessary to throw gold into the hollow cavity left behind. After burn out, the flask is placed in a cradle on a swing arm in direct alignment with a crucible in which gold or platinum will be melted. Depending on the equipment and user preference, the crucible will be heated by high frequency, induction, or a torch to melt the metal, while the arm is in a cocked position. When the precious metal is at critical temperature, the centrifuge is released and metal is slung from the crucible at high velocity, filling the flask before it spins to rest.

The principle of vacuum casting is very similar to centrifugal casting. Once again, the molten gold must be fed into the flask with sufficient thrust to allow it to flow through the small cavity before cooling. The equipment used for vacuum casting requires the sand box to be placed in a sleeve inside the cavity, in order to create a forced vacuum during pouring or releasing the molten metal into the mold.

Once the flasks are filled it is necessary to remove the precious metal castings. The hollow impression in plaster, filled with glowing red platinum or gold castings, is lifted from the casting equipment with tongs. Depending on color, carat, or metal used, they are quenched in water or left to cool. When the flasks are cooled, the investment form is destroyed while the remaining plaster is chipped away, leaving behind a tree containing models as branches. The models are then cut free from the sprue and forwarded to jewelers who will execute jewelry polishing, jewelry fabrication, and stone setting to transform the casting into fine jewelry.