Mine is a gold mine in an ex-Soviet "stan" country, where the 50/50 venture turned into a total loss for shareholders within one of the 50s, as the mafia hoodlums posing as a government one day decided to turn their 50 into 100 by appropriating all assets (as well as kidnapping a few people to make sure there were no issues with the outcome). This is the only time I've lost an entire investment, and in fact it's the only bad investment I've ever made; the rest have all either been out-and-out winners, or I've sold at a reasonably break-even point where I see no future and can use the capital elsewhere. It's hard to learn from this failed venture, however, as at around the same time I made a bundle on a listed copper mine within another dodgy "stan". I guess you could say only do mining investments in politically stable countries with cultures that value words written in contract - but where would be the fun in that?