chess etiquette

When should you resign?  Some resign as soon as the queen is lost.  Some resign when a loss is assured.  But I, as a novice, keep playing till the very end.  At my level, I and my opponent need to learn endgame.  If I resign, I deprive my opponent endgame development.  I assume there is a certain level of play, that resigning is appropriate.  Where is the demarcation?

So, when I play to the end and don't resign, I am not breaking some chess etiquette rule then.

but make sure to resign if you lose your queen 

(queens gambit reference very funny)

A rite of passage is a ceremony or ritual of the passage which occurs when an individual leaves one group to enter another. It involves a significant change of status in society.

Learning/ becoming aware of when it’s time to resign becomes a “ rite of passage “ for the chess player.

Resign when you feel that there's nothing more to be learned from continuing.

A good way to put it.

Rule of thumb: There are two situations where you should keep playing, even if you're sure you're losing:

1. If there's something you can learn from playing out the position. For instance, if you're down a piece, but you don't know how you would finish off the opponent if the positions were reversed. Play it out to learn from your opponent's technique.

2. If there's a chance your opponent could screw up and lose their advantage. This won't happen if you're playing a master or grandmaster. But if they're not jerks, most of them will understand if you keep playing for reason #1, above. Against your fellow novices, they could easily blunder back, so feel free to give them every opportunity to do so. Against players who are between those two extremes, it's a judgment call, which is why it's considered a sign of respect to resign. It's like you're saying that you respect your opponent's skill enough to assume they can play it out without blundering.

Depends on your rating honestly at my level I sometimes resign if I lose a knight depending on my opponent. It all depends on postion but for the most part I consider it a sign of respect.

Rules of thumb in Chess? Come now ... one may resign after a silly mistake early on- that day not wanting to battle on. Seek another game. Another day - decide to play it out being in a fighting mood. There is no rule of thumb. 

Probably when you no longer have anything to learn from persevering with lost games. You answered it yourself!!