Update:
I posted last week or so about a black jade piece in question. Thankfully, Crosso, 2boys_jademommy and Silver Mom were quick to help me out and ease my anxiety by showing me their own black jade pieces.
After a week with the gemologist and consulting other experts - they did confirm that my bangle is a true natural black jade!
Although, they didn't specify whether it was nephrite or jadeite but oh well.... I can rest assure and enjoy my bangle for years to come!
Here is a picture of it!
It's a pure opaque jet black jade with such a shiny finish! It's as black as black can be!