Hi goldnugget
That is a beautiful natural pearl. It has the slight lines deep under the surface that my natural Bahraini baroque pearl has. I have never seen lines like that in a cultured pearl. The color is not like any Gulf pearls I have seen. I would think Slreap might be right about the origin because it is a very rare color in Gulf Pearls.
If the photos are true to color- that is as close to genuine padparadscha color in a pearl you are going to see and is probably why slraep mentioned the saltwater/freshwater phenomenon of the Bangladesh pearls which produces colors like this one.
All in all I think this pearl has precisely the spiritual qualities Indians (esp Hindus) prize in a pearl and you are quite a lucky guy to be its caretaker for this generation.
You are also lucky to have a friend with such a collection and expertise. I hope he lets you look at his treasures and learn about their many spiritual qualites- this is just too good an opportunity to miss!