Swiss gem dealer PG Services supplies rare colored diamonds to collectors and ensures its clients receive expert investment advice from top gem industry experts. The company's 2020 report showed that luxury investments, including colored diamonds, grew in value by 14.6% annually from 2008 to 2012, with a rare 60 carat pink diamond recently selling for $83 million and a 5 carat blue diamond selling for over $6 million, demonstrating that colored diamonds appreciate better than most other luxury goods.