Nugget

nugget, in mining, water-worn, solid lump of metal; the word is most commonly used in reference to gold, but copper, silver, platinum, and other metals in this form are also designated as nuggets. Fragments and pieces of vein metal whose history does not include fluvial (water) transport are not called nuggets. Gold nuggets commonly range from the size of a pea to that of a nut; exceptionally large ones include the 64.75-kilogram (2,284-ounce) “Welcome Stranger” from Ballarat, Australia, and the 49.41-kilogram (1,743-ounce) “Blanche Barkley” from Kingower, Australia.