this is my 200th post! in celebration, you can see how some items of jewellery can be reproduced.
this first kind of mold is a cold mold, and consists of pouring a certain liquid (i can't remember the brand Robin uses right now) around the object into a rectangular frame that is sealed off. after it sets for a day or so you can cut it open to reveal the piece again. this mold can be used on pieces that aren't metal since no heat is required. which means you can make molds of wax carvings and plastics, or organic materials such as twigs and leaves.
after cutting the mold apart very carefully with an extremely sharp scalpel, you can inject wax into the small opening (the area where the wire is sticking out) to get an exact replica of your piece in wax form as many times as you'd like. then voila! you can then use that wax to cast the copy into metal.
don't mind my disgusting fingers - this is how jewellers hands normally look until we leave the studio. gross right?