Carefree talking brings confusion.
What you say (i.e. that the large bead in Carl's necklace is not made of amber, but of copal) makes things much more understandable to me. So, many many beads sold/brought as amber are really copal. And of course, it makes sense: the less fossilized resin ages faster/easier.
And yes, of course you are right: the 2nd. "type of opacity" I was speaking of is not real opacity, but just a surface erosion screening the inner translucence.
And evidently "massage" was just a punt: what is instrumental is oiling. I did not know heat is also a recommended procedure: I will try it!
Thank you for careful checking our posts.