Old, but article that applies to today.
http://www.thestreet.com/story/10457240/2/bolling-the-gold-and-platinum-connection.html
"Over my 22 years trading, I have watched the relationship between gold and platinum prices. It is a rare occurrence that platinum, the more precious metal , has traded down to the gold price. It happened in 1987 after the crash. It also happened in 1991 and 1997. But only in 1991 did platinum dip below gold. On all occasions platinum rallied substantially after the parity price. In 1987, platinum went $235 over gold ($635 vs. $400). After a brief week trading parity in 1997, platinum took off and has never looked back, trading a whopping $1165 over gold ($2200 vs. $1035)."
http://www.thestreet.com/story/10457240/2/bolling-the-gold-and-platinum-connection.html
"Over my 22 years trading, I have watched the relationship between gold and platinum prices. It is a rare occurrence that platinum, the more precious metal , has traded down to the gold price. It happened in 1987 after the crash. It also happened in 1991 and 1997. But only in 1991 did platinum dip below gold. On all occasions platinum rallied substantially after the parity price. In 1987, platinum went $235 over gold ($635 vs. $400). After a brief week trading parity in 1997, platinum took off and has never looked back, trading a whopping $1165 over gold ($2200 vs. $1035)."