Re: I did that once too...
That depends on which acid you are using, calcium carbonate reacts to give a coating of calcium sulphate which inhibits further reaction when using sulphuric acid. Use aqua regia as it gets the job of getting rid of the skeleton done.
Calcium Chloride is soluble, and won't form a coating, so hydrochloric acid will do the job.
You cartainly don't want to use aqua regia if you're hoping to sell any gold fillings, afterwards ...
Biting the hand that feeds IT
