A new exchange-traded fund that tracks diamonds and gems. Probably might offer some diversification in a portfolio. Someone with a lot of value in stones might short this fund to help protect the collection's value against possible overall drops in gem prices.
http://www.nationaljeweler.com/nj/diamonds/a/~29624-New-ETF-tracking-diamond-gem
http://www.nationaljeweler.com/nj/diamonds/a/~29624-New-ETF-tracking-diamond-gem