How heavy is the heaviest gold nugget in kilograms?

Answer 1

The heaviest good nugget ever was the "Welcome Stranger" which measured 61 cm by 31 cm and was discovered by John Deason and Richard Oates at Moliagul, western Victoria, Australia on 5 February 1869. It weighed 2316 troy ounces or 72.04 kg. The Welcome Stranger is not the same as the "Welcome Nugget" found in Ballarat in 1858 which was the largest single nugget prior to the discovery of the Welcome Stranger.
However, larger than this is the Beyers and Holtermann nugget, the largest single piece of reef gold ever discovered in the world. The Beyers and Holtermann nugget was, strictly speaking, not a nugget, but what is called a matrix. Weighing in around 286 kilograms(about 630 pounds), it measured 150cm by 66cm, and was worth at least £12,000 at the time it was discovered, in October 1872. It was discovered by workers at the Star of Hope Gold Mining Co on Hawkins Hill, at the Hill End goldfields in New South Wales, Australia. Gold sometimes appears as a "vein" included in rock, usually quartz. In this case it was a quartz reef. By removing the rock around the vein, the gold included in that vein can be recovered in one piece. And that was the case with the Holtermann Nugget.