, or a cube 21.0 m on a side. The world consumption of new gold produced is about 50% in jewelry, 40% in investments, and 10% in industry. [ 3 ] Besides its widespread monetary and symbolic functions, gold has many practical uses in dentistry , electronics , and other fields. Its high malleability , ductility , resistance to corrosion and most other chemical reactions, and conductivity of electricity have led to many uses, including electric wiring , colored-glass production, and gold leafing . A schematic diagram of a NE (left) to SW (right) cross-section through the 2.020 billion year old Vredefort impact crater in South Africa and how it distorted the contemporary geological structures. The present erosion level is shown. Johannesburg is located where the Witwatersrand Basin (the yellow layer) is exposed at the "present surface" line, just inside the crater rim, on the left. Not to scale. Most of the Earth's gold probably lies at its core, the metal's high density having made it sink there in the planet's youth. Virtually all discovered gold is considered to have been deposited later by meteorites that contained the element. [ 4 ] [ 5 ] [ 6 ] [ 7 ] [ 8 ] The asteroid that formed Vredefort crater 2.020 billion years ago is often credited with seeding the Witwatersrand basin in South Africa with the richest gold deposits on earth. [ 9 ] [ 10 ] [ 11 ] [ 12 ] However, the gold bearing Witwatersrand rocks