There is almost no gold in it. 18k gold is 75% gold by weight, not volume. Apple created an alloy that, in addition to the normal metals, is mostly lightweight ceramic.

At the time I was surprised there wasn’t a class action suit. They were charging an amount that was in line with real gold watches and yeah the “gold” part was 75% gold by weight but it was such a departure from anything else ever called 18k gold it just seemed like a straight up scam to me.