Indole isn't a rare note, you can get it with: syntetic molecules, overdose of white flowers (orange blossom and jasmin in primis), cumin, in example. Ambrette seeds are rarer and sparkling, but I love them.
Obviuosy the natural animal scent is more depth, sparkling, complex, hypnotic. Lately I've been able to sniff a parfum with tons of Haiti Burbon Vetiver and tons of natural Ambregris, sublimated, and I couldn't remove the nose of my wrist. A beauty and, repeat, a DEPTH that can be understood only by trying.