Magnesium is a chemical element with symbol Mg and atomic number 12. It is a shiny gray solid which bears a close physical resemblance to the other five elements in the second column (Group 2, or alkaline earth metals) of the periodic table:
M 0642 (OTTO) Magnesium slug, 3.175mm (0.125in) dia x 3.175mm (0.125in) length, unannealed, 99.95% - used for manufacturing of mobile phones, laptop and tablet computers, cameras, and other electronic components.