These pieces were sintered in a coal based charcoal which yields some really varied and interesting patina on the bronze. They will get a little brass brushing to bring out the shine.
Bronzclay is one of the many precious metal clay products on the jewelry market. It's made up of microscopic metal particles mixed with an organic binder and water. You can shape, mold and texture the clay, then dry it, refine it and cook it in a kiln at 1550 degrees for almost nine hours. In the end (usually) you end up with some really nice bronze, copper or silver pieces (depending on the clay you use) that are uniquely yours.
It can be tricky, sometimes the clay doesn't sinter well and the metal pieces are brittle and useless. When it works the pieces are fabulous.
I'm very happy with these. The little hearts are my favorite.