An intricately folded gold nugget turned out to be the largest individual crystal of gold ever found. Earlier this month, scientists at Los Alamos National Laboratory verified that the 7.68-ounce (217.78-gram) lump -- about the weight of a large onion -- is a single, intact gold crystal. With that crystalline pedigree, the value of the nugget rocketed in value from $10,000 to $1.5 million.
Gold normally forms smaller cubic, 8-sided or 12-sided crystals, according to Mineralogy Database. But larger, irregular structures also can form.
Nuggets of gold generally consist of a collection of these crystals pressed together. Geologists and miners rarely find a nugget made up of only one crystal. Decades, ago miners excavated the recently confirmed champion gold crystal in Venezuela. However, controversy surrounded the nugget. In 2006 the nugget was rejected by an auction because of questions over authenticity.
To prove the crystal's integrity, scientists at Los Alamos National Laboratory's Lujan Neutron Scattering Center used two devices. One used sub-atomic particles, called neutrons, to peer inside the nugget and determine its atomic arrangement. The other instrument measured the crystal structure of the gold piece.
However, at only 217 grams, the gold crystal doesn't come close to topping the largest nugget ever found. In 1890, miners uncovered a 173- pound (78-kilogram) nugget in Australia, according to the University of California, Santa Barbara's ScienceLine. The Banco Central Museum in Brazil displays possibly the largest nugget still in existence. That gold behemoth weighs 60.82 kg and contains 52.33 kg of gold.