The Tanzanian miner and father-of-30 children who became an overnight millionaire after digging up two massive chunks of one of the world's rarest gemstones worth $3.35million, has found a third multi-million-dollar lump of Tanzanite.

The third stone allegedly weighs six kilograms and has an estimated value of $2million (£1.5million ).  

Mr. Saniniu Laizer found Tanzanite, which has a deep violet-blue colour, near his home in northern Tanzania, according to local report. 

The 52-year-old, who has four wives and 30 children, previously vowed to use some of his earnings to build a school and a shopping mall in his community, where many parents can't afford to pay for their children's education.  

Last month, the Tanzanian government gave Saniniu a cheque for 7.74 billion Tanzanian shillings ($3.35million) for the first two stones which weighed 9.2kg and 5.8kg