Help with selecting older turquoise pieces

I’m a new member and have just become interested in turquoise. I am confused on what is considered chips or damages in the turquoise versus flaws in the stone that might be considered acceptable. I read that chips or cracks in turquoise can significantly affect the value.
I have attached a photo of turquoise from a cuff that I purchased. The seller didn’t identify any problems with the turquoise but when I look at the turquoise under magnification, several of the darker areas appear to be chipped and not level with the rest of the stone. I can see rock coming through on several of the larger areas. In two places on the very edge it appears to have been stabilized at some point as it has a shiny plastic look and is a different color.
So my question is above are these considered natural flaws or damage. What is considered acceptable? I think this is a beautiful older piece but don’t want to pay good money if the value is not there. Thanks for your help

This stone looks fine.

Sorry I have this double post going. I was responding to the other post but see you evaluation here is no damage. It helps me a lot. One other question, if there is a crack to the metal work behind the stone but the stone is secure is it best to leave alone or repair?