The word "diamond" comes from the ancient Greek "adamas" -- invincible. A diamond is the hardest substance found in nature and the most precious. For centuries, diamonds have served as the ultimate shorthand (or substitute!) for something far more elusive: true love itself.
But a new Hollywood film threatens to chip away at the luster of these magnificent stones. "Blood Diamond," starring Leonardo DiCaprio and Djimon Hounsou, chronicles how diamonds funded decades of civil war in Africa.
In Sierra Leone, Congo, Angola and Ivory Coast during the 1990s, diamonds kept the guns and the bloodshed flowing. According to the watchdog groups Global Witness and Amnesty International, conflict diamonds accounted for 15 percent of the global market. In Angola alone, the rebel group Unita generated as much as $4 billion from diamonds.
Human rights groups say that diamonds remain an important source of funding for the Russian mafia, Hezbollah and even al Qaeda.
"Diamonds to them are very useful," said Alex Yearsley of London-based Global Witness. "There are no serial numbers, they don't set off metal detectors in airports, and they maintain their value."
That's why the most concentrated form of wealth on earth is also the very currency of conflict.
The fact that a new Christmas action movie, set in 1999, calls attention to conflict diamonds has the industry nervous. "Blood Diamond" is a potential poison pill for retailers.
After all, this is high season for marriage proposals. December and the run-up to Valentine's Day account for as much as one-quarter of the marriage proposals each year.
"When you hear about a Hollywood movie with a title like this one, you can't help but be a little anxious about it," De Beers spokesman Stephen Lussier told "Nightline." He was eager to set the record straight.
For the past three years, the global diamond industry has taken significant steps to address the problem of conflict diamonds, adopting a vetting system called the Kimberly Process. Adopted by 70 countries, the Kimberly Process vouchsafes the source of each diamond sold.
Stephen Lussier insisted that as a result "significantly less than 1 percent" of the diamonds sold worldwide are conflict diamonds. He said all of the diamonds De Beers sells are legitimately mined.
De Beers gave "Nightline" access to its flagship mine in Botswana, a huge crater that accounts for 50 percent of the country's government revenues. Diamonds from that mine have paid for state-of-the-art schools and medical clinics for the workers.
Human rights groups say the Kimberly Process has helped. They say it has also helped that many African civil wars are over. But they say there are still huge loopholes that allow illicit diamond traders to prosper.
"The Kimberly Process has been described by some in the industry as little more than a fig leaf," said Yearsley. "It's a way of covering up illicit diamonds as well."
Ghana now faces possible expulsion from the Kimberly Process. Unscrupulous traders there have laundered illicit diamonds from neighboring Ivory Coast, where a bloody conflict is still raging. The diamonds that pass through Ghana, including the ones smuggled from Ivory Coast, are certified "conflict free."