Stocks, funds and bonds are investment vehicles any savvy investor will have in his or her portfolio. But, if you are thinking about diversification, consider these unusual and alternative investments. Investment-grade Diamonds Diamonds are bullshit, as Rohin Dhar of Priceonomics puts it, and his assertions are right on the money. However, look past the commercial jewellers and their shiny but worthless wares, and you’ll find a world of diamond investors reaping eye-popping returns from small, shiny rocks. A few months ago, Sotheby’s Hong Kong put an internally flawless 8.41-carat fancy pink diamond under the hammer. A bidding war ensued for this rare and desirable stone and when the dust settled, the winning price was a record-breaking US$17.77 million. The previous record was set in 2009 when an undisclosed bidder paid US$2.1 million per carat for a similar fancy pink diamond. “The advantage of diamonds is ......