The best, and I mean the most definitive source of meditation information is at http://www.MeditationExpert.com which has lots of free articles and downloads, including some information on gold for samadhi attainemnt ( a high meditative state).
Gold was used - though VERY RARELY -- to help adepts attain various meditative states in ancient China. This was a practice in Taoism. However, for meditative purposes, it is NOT something you want to take every day. It was only used rarely, and for a boost.
At this site, you can read about the ancient chinese using the meat of a special bird for gold poisoning or Sechuan peppers when they consumed too much silver.
Incidentallyy, the site offers a book http://www.meditationexpert.com/stubborninfections.html which tells how the Taoists would use arsenic to kill off germs to help with meditation, though the same effects can be done with colloidal silver today.