I'm pretty sure that Apple uses a very conventional gold alloy with a similar density as other gold alloys. Somewhere on their website they provide the weight o

I'm pretty sure that Apple uses a very conventional gold alloy with a similar density as other gold alloys. Somewhere on their website they provide the weight of the cases and the bands. A quick back-of-the-envelope calculation shows that their gold is twice as heavy as their stainless steel. They are pretty specific on the steel they use, so we know it's density is 8g/cm^3, meaning their gold is roughly 16g/cm^3. This means their gold is probably a completely normal alloy, not some ceramic composite as some people believe. We also see their yellow gold models are slightly heavier than the rose gold models, which is expected, since the silver/copper ratio is slightly larger in yellow gold, and silver is denser than copper. Sources: http://robservatory.com/the-all-in-one-apple-watch-spreadsheet/ http://robservatory.com/the-all-in-one-apple-watch-spreadshe... http://leancrew.com/all-this/2015/03/apple-gold/ http://leancrew.com/all-this/2015/03/apple-gold/