Diamonds are a girl's best friend - or so the saying goes anyway.

But do girls ever wonder where these precious stones come from?

'Blood Diamond', a new picture from director Edward Zwick focusses on the diamond trade, and specifically on the diamond trade and its links to violent conflict in Africa in the 1990s.

Set mainly in Sierra Leone at a time when the country is being torn apart by an incredibly violent civil war 'Blood Diamond' stars Leonard DiCaprio as Danny Archer, a white diamond smuggler from Zimbabwe, who spends his life living on the edge to buy and smuggle diamonds across the border for his wealthy South African employer.

In a violent beginning the viewer sees Sierra Leone rebels attacking small rural villages, shooting indiscriminately and chopping off the hands of locals so that they will be unable to vote in the country's elections.

While murdering and mutilating the villagers the rebels come across Solomon Vandy (played by Djimon Hounsou) whose life is spared as he appears strong enough to mine for diamonds.

He joins hundreds of others as rebel prisoners forced to work all day mining the precious stones.

The first time we meet Danny Archer he is supplying the rebel war lords with South African weapons in exchange for diamonds, which he then must smuggle across the border out of Sierra Leone into Liberia.

Solomon and Danny's paths first cross when they end up in a Freetown jail at the same time.

Before he was rescued from the rebel mine Solomon discovered a large raw diamond known as a 'pink' and was able to hide it. But when Danny overhears this (in the jail) he simply has to get his hands on that diamond.

While in Freetown Danny bumps into a beautiful American journalist Maddy Bowen (played by Jennifer Connelly) who is working on a story about 'blood diamonds' for her magazine.

A blood diamond - also called a conflict diamond or a war diamond - is a diamond mined in a war zone and sold, usually clandestinely, in order to finance an insurgent or invading army's war efforts.

Maddy quickly figures out that Danny is a smuggler and seeks his help with her article and, although he is initially wary of her, the two soon become close and rely on each other both for information and to survive in a country on the brink of tearing itself apart in a bloody civil war.

As Freetown self-destructs all three set out across the country together although their respective quests are very different - Solomon wants to find his family, Danny wants the 'pink' and Maddy wants a story about 'blood diamonds'.

Although there are many good things about 'Blood Diamond' the film itself never is quite as good as the director wanted it to be.

With all the action and all the brutal violence the message the film is trying to punch home gets diluted and almost lost in the gun smoke.

Although it starts out with worthy intentions the film descends into an action adventure following our three heroes from one gun battle to another as they dodge bullets coming from all sides. Indeed, in many of the gun fights the sides get blurred and it becomes a struggle to make out the bad guys from the even worse guys - there are no good guys in this part of Africa, so it would appear.

Leonardo DiCaprio has been nominated for an Oscar for his part in this film and he may just deserve that nomination. But the film is, rightly, nowhere to be seen on any award nomination list.

Supporting DiCaprio, Connelly is good as the action junkie journalist willing to risk all for her story while Djimon Hounsou is excellent as the black father whose would die for the sake of his family.

With plenty of action and some brutal violence 'Blood Diamond' moves along at a fast pace. But, in saying that, the film runs for almost two and a half hours which is just too long for most people to comfortably sit through.

A severe lack of characterisation all round also takes away from the film.

In 'Blood Diamond' the black rebels are almost demon like training the young boys as killing machines when not killing themselves. And all the military seem to do here is turn up and open fire on everybody, while we only meet one or two peaceable Africans during the whole film.

No doubt there were horrific times in this part of the world but this picture doesn't further are understanding of the situation one iota.

'Blood Diamond' is an average film with above average performances. In a postscript the audience are told not to buy 'conflict diamonds' and to check where their 'best friends' have come from.

If they had put this at the start you could have gone home and not bothered watching the film at all.