(IDEX Online) - Lucky sapphire hunter Matt Betteridge found an 834-carat monster thanks to heavy rains in Queensland, Australia.He was out "specking" - scanning the ground for precious gems - when he chanced upon the stone, which was the size of a "small child's fist". It's been valued at AUD $12,500 (USD $8,000).Speckers often go out after wet weather because rain washes away the topsoil, exposing sapphires. Mr Betteridge was close to his home in Rubyvale, in the Gemfields region, known as one of the largest sapphire-bearing areas in the world.The Gemmological Association of Australia said any sapphire over five-carats was very rare, and 834 carats was phenomenal.Pic courtesy Matt Betteridge.