I use a brand called Precious Metal Clay (PMC) in my classes.
PMC was initially developed by scientists working at the Mitsubishi Materials Special Products division in Sanda, Japan. After years of experimentation the first patents were awarded in the early 1990s with many additional materials joining the family of products.
The principle ingredient of PMC3 is silver, reduced to tiny flakes smaller than 20 microns in size. As a point of reference, it would take as many as 25 of these particles clumped together to equal a grain of salt. The other ingredients in PMC are water and an organic (naturally occurring) binder.
After firing, the water and binder have completely burned away so what remains can be hallmarked as .999
Dried out or unwanted objects can be recycled / refined just like conventional precious metal.
How Does It Work?
Under the proper conditions, crystals of metal fuse together in the same way that droplets of water run together to make larger puddles on the window pane. In the case of metals, oxides (tarnish) that form naturally on most metals prevent this from happening. The solution here is to use precious or noble metals in their pure state. These do not readily oxidize so even at the high temperatures needed to induce fusion they remain free of coatings.
There are different forms of Metal Clay available
The most popular form because from here you can make sheet, wire, paste and volumetric forms.
This material is specially formulated to allow it to be pressed through a nozzle. If you have ever decorated a cake you can master PMC Slip. Sold loaded into a disposable syringe.
A thick slurry that is used to fill joints, adhere parts and create luscious frosting-like surfaces.
Mitsubishi developed this for the Japanese art of origami, but American artists have found this thin leathery sheet useful for weaving, braiding and to create drapery effects.
Thicker version of the paper, excellent for rings, backing plates, medallions and more.