Old find, I dont have reliable info on when or where but it's part of a collection that was almost entirely found in the northern most part of Michigan's upper peninsula if that helps. It's very soft and easily scratched.
Calcite was my first thought, too.
Then seen the black specks, thought quartz
but you said it scratched real easy, so Calcite
(I'm not very good at this, lol)
Nice specimen, though!
Calcite on an limestone matrix IMO. I have a friend that collects lots of Calcite from the UP, most of it is yellow, but I have also seen white/clear in his collection. The "tubes" in pic three may be crinoind stems, which are a very prolific fossil from up there.