- Little Piney, Pulaski County, Missouri, United States1
- Long Branch, Monmouth County, New Jersey, United States1
- Lord Dudley's Mine, Dudley, West Midlands, England, United Kingdom1
- Los Angeles, Los Angeles County, California, United States1
- Louisville, Jefferson County, Kentucky, United States1
- Lubietova, Banskobystricky, Slovakia1
- Lycoming County, Pennsylvania, United States1
- Lyme Regis, Dorset County, England, United Kingdom1
- Macon County, Wilcox County, Alabama, United States1
- Magnet Cove, Hot Spring County, Arkansas, United States1
- Maine, United States1
- Malacca, Malaysia1
- Manilla, Philippines1
- Mansons Mine, Bucks County, Pennsylvania, United States1
- Maryland1
- Maryland, United States1
- Massachusetts1
- Matlock, Derbyshire, England, United Kingdom1
- Mayesville, Sumter County, South Carolina, United States1
- Mazatlan, Mexico1