Mattson, Linda. History of the Village of Otter Lake, Lapeer County, Michigan. CMU Term Paper, 1971. Metamora Among the Hills: A History. Metamora Township, MI: Metamora Friends of the Library, 1979. Porter, Floyd W. The Triumphs of His Grace; A Pilgrimage of More than 140 Years by the People of God, Called Methodist at Lapeer, Michigan.
The Cullinan, which was found near Pretoria more than a century ago, was until recently acknowledged to be the largest cut diamond in the world, weighing in at 530.20 carats. In 1985 it lost the record to the Golden Jubilee, which was found in the same mine as the Cullinan and weighed 545.67 carats.
Kimberley Diamond Mine, South Africa. The Kimberley Diamond Mine (also known as the Big Hole) holds the (disputed) title of being the largest hand-dug hole in the world. From 1866 to 1914 50,000 miners dug the hole with picks and shovels, yielding 2,722 kg of diamonds. Attempts are being made to have it registered as a world heritage site.