What is the "crater of diamonds" state park in Arkansas and how was it formed?

Answer 1

When a volcano forms it can leave a lava pipe. If that lava pipe is put under a lot of pressure and high heat then it can form diamonds. If that old lava pipe erodes it can leave diamonds. Many were once found on beaches in South Africa until we discovered the Kimberly Diamond Pipe and realized how diamonds were actually formed; a similar event happened in North America, in Arkansas.

According to Wikipedia: http://en.wikipedia.org/wiki/Crater_of_Diamonds_State_Park
“The Crater of Diamonds State Park is an Arkansas State Park located near Murfreesboro in Pike County, Arkansas, USA containing the only diamond bearing site in the world that is open to the public….

The Crater of Diamonds State Park is an 911 acre (3.69 km²) Arkansas State Park situated over an eroded lamproite volcanic pipe. The park is open to the public and, for a small fee, rockhounds and visitors can dig for diamonds and other gemstones. Park visitors find more than 600 diamonds each year of all colors and grades. Over 25,000 diamonds have been found in the crater since it became a state park. Visitors may keep any gemstone they find regardless of its value (and some, as listed below, have been quite valuable).”