The characteristic or quality of being gritty.(noun)
Wiktionary.org : Text is available under the Creative Commons Attribution-ShareAlike License
Use "grittiness" in a sentence
"Just as significantly, the overwhelming superiority shown by the European players, in grittiness of attitude and quality of golf, suggested a psychological advantage that will be difficult to overcome."
"Giants) are our mirror image in grittiness, Percival said."
"And by grittiness I mean that Ron vomits up slugs at one point."