Wow, loosing a toenail is common in skiing? -I must not be skiing hard enough. . . I would love to hear more about this phenomenon if someone would care to elaborate about why this happens.
The nail will not necessary turn black before you loose it. As a construction worker I've lost a fair share, and most of the time the nail will almost instantly turn a dark crimson red, and then progress to a purple/black. My last loss occured after getting in a pichpoint between a heavy load and a steel bar. -I was surprised that there was no discoloration whatsoever. Especially since I thought my finger was going to get pinched off.
After a few days I noticed clear liquid oozing out from under the nail, the nail started to lift, and then off it came, in one solid piece. It was surprisingly elegant and painless, but most of all lucky.