sounds like an inlay to me. gold is maleable. so it will be easier with chewing. it will wear with the opposing tooth. but it's also very conducive to temp. it might end up being pretty sensitive to extreme temps. watch out, though, they absolutely do mix it with other metals.

the dentist i used to work for did about 10 - 15 of these a year. very easy. almost like a partial crown. same procedure. they'll clean out the decay. take an impression (hardest part for most patients). then most likely put a temporary filling in there. you'll come back 7-10 days for placement of the final filling.

edit: found this "It is not completely pure but a mixture of gold, silver, platinum, copper, palladium, and zinc."