How to determine ruby source?

I have an old ruby gemstone set in silver ring. The stone was bought by my late father in 1970s. The weight is approximately 5 carats and the stone was cut cabochon. The ruby has a vivid hot pinkish red color, but also a color zoning which the color is softer and got an asterism in there (35% length of the stone). The gemstone is included especially in the softer red-pink zone while at the vivid red zone is much cleaner.

I tested it at the local gem lab, says it doesn't show any signs of treatment. But shame, It also doesn't explain where did this ruby came from. When I look at it with 10x magnifier, I can see tiny cracks all over the ruby. I also tested it with UV light and it burns orangish-red, so maybe it doesn't came from Thailand. Either it's from Myanmar or Africa.

Is it possible for me to find out where did this gemstone came from?