Some that I have been making, resin with other "stuff" inside of it. There is no polishing these on the buffing wheel, the aluminum will ruin a good buffing wheel. Luckily I remembered that from the last time I did this. I also made some up with brass, will try to do them in the next week or so. The aluminum looks like silver and the brass looks like gold. The denim is a real pain to sand but does sand since it has been impregnated with resin.
Marvin
This one is resin and aluminum.
This one has denim and more aluminum.