A pastor working in the mines of eastern Sierra Leone has unearthed a 706-carat diamond. Experts say the stone could rank as the 10th largest ever found. The huge diamond was discovered by Emmanuel Momoh, one of thousands of Sierra Leoneans who seek their fortunes in the informal mining sector that dominates the diamond-rich Kono region. This is the biggest diamond find since 1971. The stone was presented to the country's President Ernest Bai Koroma.