I think you'd see more traditional bartering than money being introduced again in its earliest stages.
Jewelry demand wouldn't help, either. If the price of gold went to 0, how much would be used in jewelry? Sure, it's pretty, but being expensive is part of the point.
Gold is directly useful for a huge range of things and the use in industry provides a very real price floor.
Bitcoin, on the other hand, is still firmly in KBC territory.
That outcome will likely also result in a further 50x return from here, or a further decline.