Some movies entertain. Some challenge the way you think, encouraging you to see the world in a different way. And some try to change the way you live.

Blood Diamond does all three.

Yes, it was violent. Yes, there were innocents killed; there were angry soldiers; there was racism and cruelty and drugs and child kidnappings. But for me, the hardest part about watching this movie was not the violence, seeing children being brainwashed and made to be soldiers, or watching ordinary people kidnapped and turned into slaves. The hardest part was remembering the wedding ring was on my finger, and not knowing where its diamonds came from.

Blood Diamond tells the story of Solomon Vandy (Djimon Hounsou), a fisherman in 1990s Sierra Leone whose village is attacked by the Revolution United Front—the rebel army in an ongoing civil war. The RUF capture him, separating him from his wife and children, and put him to work in a diamond mine. There he finds a diamond—a rare and extremely large pink diamond. He knows it’s worth a huge sum, enough to rescue him and help him find his family if he can keep it for himself. But he also knows that the soldiers will kill him if he doesn’t immediately give it to them. Miraculously (albeit improbably), he manages to hide it, burying it beside the river just before the RUF camp is attacked by government soldiers.

But that’s when his troubles really start.

Vandy is quickly surrounded by a variety of people who all want the diamond for themselves. From the RUF soldiers to diamond smuggler Danny Archer (brilliantly performed by Leonardo di Caprio), everyone sees the big diamond as the only tool that will get them what they want. Even altruistic journalist Maddy Bowen (Jennifer Connelly) values the diamond—and the man who knows its location—as much for the story they can give her magazine as for their intrinsic worth. But ultimately, both the characters and the diamond itself grow to become something greater than they are. The hero of the story turns out to be the least likely: mercenary Archer rises above self-interest to sacrifice for someone else. By doing so, he not only helps a friend; he transforms the diamond. From being a fund for terrorism and the means for empowering a bloody civil war, the diamond becomes a tool that enables one man to find his family and help them escape an intolerable situation.

And though the movie doesn’t overtly say it, that is exactly the problem with diamonds: they are always a double-edged sword. On the one hand, there are still an estimated $23 million of conflict diamonds being smuggled into the international market each year. On the other, diamonds are one of the biggest sources of legitimate income for many African countries, and they have been the foundation of wealth for many rising nations. Even the titular blood diamond of the movie is sold not for profit, guns, or blood, but for freedom. This diamond, at least, is worth its price.

Blood Diamond has been criticized for being too heavy-handed in message—an unfair accusation, considering the ambiguous nature of the diamond in the movie--and interweaving too many characters, issues, and plotlines (one major storyline shows Vandy’s son being brainwashed into a child soldier). But Blood Diamond is a perfect example of the political and moral power that a movie can potentially exert. The issue of conflict diamonds is not a new one; activists have fought for years to bring this issue to the consciousness of consumers. The U.N.-sanctioned Kimberly Process for the certification of conflict-free diamonds has been in place since 2003, but today, blood diamonds are still an ongoing issue and a significant source of funds for terrorists and illegal armed operations. It remains to be seen whether Blood Diamond will succeed in making this problem one in which consumers, not just activists, insist on change. But if anything could achieve that, this movie should.