Model Naomi Campbell testified at the war crimes trial of former Liberian ruler Charles Taylor on Thursday that she received a gift of "dirty-looking stones" after attending a dinner with him — but stopped short of saying they were diamonds or that she was given them by Taylor himself.Campbell was being questioned about claims made by actress Mia Farrow that Taylor gave the model an uncut diamond or diamonds after a dinner party hosted by Nelson Mandela they all attended in South Africa in 1997.Prosecutors say Campbell's testimony could provide evidence he received diamonds from Sierra Leone rebels in exchange for weapons during that country's 1992-2002 civil war.The British model said on the stand she was awakened in the middle of the night by two black men at her door who offered her a pouch they said was a gift for her. She said she didn't look at it until the following morning."I saw a few stones in there. And they were small dirty-looking stones," she said.She said that the following morning Farrow told her the rocks must be diamonds and were probably a gift from Taylor. She said she gave them to a friend who did charity work in South Africa.The British model, who had fought to avoid testifying, arrived at the courthouse in The Hague on Thursday surrounded by police escorts.Entering the courtroom wearing a beige 2-piece suit and fashionably late — several minutes after she was first summoned to take the stand — Campbell was calm and composed as she answered questions from prosecutor Brenda Hollis.Prosecutors say that from his seat of power in Liberia, Taylor armed, trained and commanded Sierra Leone rebels who murdered and mutilated thousands of civilians across the border. Taylor has said he is innocent of the 11 war crimes charges he faces, including murder, rape, sexual enslavement and recruiting child soldiers.