I just started experimenting with a new way to turn natural objects into metal jewelry components-- electroforming. In this process items coated with conductive paint are suspended in a solution and layers of copper slowly build up due to low-voltage electricity. You can read a more detailed explanation here.
While I make many of my pieces using the more traditional lost wax casting process, this technique is ideal for objects that are very thin, such as leaves, or large items that would be too heavy or expensive to cast.
In the photo above I have sealed and painted several different organic objects that I have gathered over the past few months. I added metal loops with super-glue, both so I could suspend them in the copper bath and then later attach them to chains or ear wires. I am intending to use the twigs to make rings.
I selected the acorn as my first experiment. It remained in the copper solution for about 4 hours. The process is not always entirely predictable and can be influenced by a variety of factors, including the amperage. Interesting surface textures can build up over time. You can notice a pebbly texture on the top loop and some grid-like lines on the bottom of the acorn.
Because the proper amperage is based on the surface area of the object, calculations for the lacy cedar sprigs or the more complicated terrain of the pine cones will be more difficult to make. I am guessing that this will get a little bit more intuitive with experience, and lots of trial and error.