A widely used measure of weight for gold is the OZ, which is equivalent to 31.1 grams. Gold is very malleable and may be extend easily so a very thin gold foil can be achieved without tearing.
Contrary to what many believe, gold has many industrial uses other than decorative. It is much better conductor of electricity than copper, for example. What happens is that it is scarce and therefore expensive, so it can only be used in industrial tasks where there is no other substitute that can meet the same or similar requirements than gold.
Another factor is that gold is the heaviest metal in the world. It is a high-density metal. We say that this guy or that book is heavier than lead, but gold is heavier. What happens is it gets expensive.
To give weight to bullets, for example, lead is often used: a lot of weight in a short volume. But it would be much better to use gold. People would have to think long before shooting someone.
