Vintage Dirty Gemstone

Hello I’ve just found this Gemstone which I’ve not spotted and cleaned, this is the state most of the stones I post was in as they was thrown in a box over a 40 year period. This one looks interesting I will have to clean it up & weigh it
Just had to weigh it & it’s 1.50ct so a good size
I’m going to clean this as I can see loads of sparkles ,coming through on the picture and that’s with all that yucky looking grime encrusted on it