Funny, as I was typing about the Witches finger earlier I was thinking about the Medusa stone, now you mention it.
Yes, Medusa stone is great too, but I think you have to be ready in a way for both. I spose it's that way with every crystal but some are easier 'accessible' than others, depending on their energies.
I'm not familiar with the other crystals you mentioned. Is sphene the same as adamite? The other one, bastnaesite, looks very interesting! I may have to remember that one
Sacred Heart crystal is wonderful! I am surprised that you know of it cos as far as I know that name was made up by the crystal shop I always go to, which is Dutch. From what I understood they were sold by the supplier as Pink Fire azeztulite, but some of those have golden healer in them as well, which makes them "Sacred Heart Crystal".
I'm curious now how you know of it, cos when I Google it, nothing comes up apart from a lot of church/chapel/religious stuff. Would you mind telling me how you've heard of it? Just curious :p