In watches, gold is 18Kt gold, which is 75% gold 25% alloy (many 18kt gold watches are marked 750, meaning its 750 parts per thousand gold, hence 75% gold 25 alloy. It would be too soft for daily wear if the gold content was higher. If something is 14Kt gold its a bit more durable but its only 58.5% gold and 41.5% alloy. Most platinum watches are 95% percent platinum (often marked PT 950), and 5% alloy, but platinum is far more durable.
all correct, as usual!
most gold watches from the brands we discuss are 18k. they used to do 14k sometimes a while back, and i have seen vintage pieces stamped 14k for lots of brands, but 18k has become the standard. as far as i see, they really do look almost the same, thought you can feel the weight difference. i really think they do it for the prestige more than anything. 18k is just fancier than 14k, and obviously the extra gold content is part of that, and, of course, adds a lot to the price.