Im sorry about your chicken. If she doesnt make it, ask the doctor to open up her crop to see if it actually was the granite.
What made your doctor suspect that it was the granite grit that caused the problem?
The "base fines" that we packed onto our driveway are really sharp, is that the same as crushed granite?
It sure hurts like heck when I get a piece in my shoe but none of the chickens, ducks, or geese have had problems with it that Ive known of. Some of the grit we give them is called granite grit but it is round little pieces that arent sharp at all and dont look "crushed". Some of the grit we have used is called pigeon grit and it is weird red colored stuff that turns my hands red. The ducks gobble that up.
Chel