I was reviewing my photos and I found I do have some chipped hooves - but only ones that have recently been deshod. So by photo number.
1 Hoof wall heavily rasped, (you can't see it but the heel is stacked too). Standard farrier approach to a hoof that is scooting forward. Weakened wall chips and breaks as nail holes grow out.
2-4 This is the hoof used in 'bull nose' (you might spot a trend developing here). Again hoof wall has been heavily rasped (note that it's a hind so has bull nosed rather than flared from metabolic problem) and nail holes are breaking even while still shod. In photo 4 you can see that nail free the hoof is just dandy but the horse has also been weaned off her pony nuts and put on a lower sugar diet.
5-6 Cardboard hoof - horse has metabolic issues big time. Very sensible farrier refused to shoe any more because of poor quality (hurrah!). In 6 you can see the hoof has grown out nicely and quality is restored.
I do have one horse that has some chips in it's bare feet - they have been left too long between trims and I am working on getting Grace to chip hers................