You know, some may be able to do better, but I must say I recently
got some of the sand cast sterling ring blanks from Thunderbird and
they aren’t bad. Rough, but that leaves room for some modification,
polishing setting options, etc. I did cut a few, anneal and resize
without much problem at all. They seemed a bit light, maybe density?
But so far so good.
So, if you want a base to start from…not bad.