Gold forms thin layers within the Earth’s crust. It can also be found in 
sand, gravel, and in streams of water caused by erosion.
Locations where gold is intermixed within layers of rock beneath the surface are called gold ore deposits. Gold can also be found in areas with active volcanoes. Historically, there have been many “gold rushes” in places like Alaska, California, and the Andes mountain range in South America. Most recently, a significant gold mine was discovered in the Andes mountains of Chile.
Gold mines are excavated similarly to other metal mines by digging deep into the ground. Sand and gravel that contain gold due to water flow are known as placer deposits. Such water flows are abundant in regions of South Africa and Australia. To extract gold, large pans and sieves are typically used to wash the mineral-rich sands.
