The Amarillo Starlight is the largest diamond found by a park visitor in the Crater of Diamonds State Park in Arkansas

Arkansas

Arkansas is a state located in the southern region of the United States. Its name is an Algonquian name of the Quapaw Indians. Arkansas shares borders with six states , and its eastern border is largely defined by the Mississippi River...

 since 1972, when it was established as a state park. The Amarillo Starlight was found by W. W. Johnson of Amarillo

Amarillo, Texas

Amarillo is the 14th-largest city, by population, in the state of Texas, the largest in the Texas Panhandle, and the seat of Potter County. A portion of the city extends into Randall County. The population was 190,695 at the 2010 census...

, Texas

Texas

Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...

 in 1975 while he was vacationing at the park with his family. When unearthed, it was a 16.37 carats (3.3 g) white diamond, but it has since been cut into a 7.54 carats (1,508 mg) marquise shape. Its value has been estimated between $150,000 and $175,000.