| Element | Osmium |
| Symbol | Os |
| Atomic Mass | 190.2 |
| Atomic Number | 76 |
| Name Origins | Greek, osme = smell |
| Year Discovered | 1803 |
| Discovered Credits | Discovered by S. Tennant at London, UK. |
| Remarks | Lustrous silvery metal of the platinum group. Unaffected by air, water, and acids, but dissolves in molten alkalis. Smells, due to formation of volatile OsO4. Used in alloys and catalysts. |
| Diagnostic Tests | There are no simple chemical tests for osmium. The element is usually found as an alloy or a sulfide mineral with other platinum group metals. Atomic Absorption Spectroscopy is used for quantitative analysis and Energy Dispersive Analysis of X-rays (EDAX) is used for qualitative analysis. |
| References | Emsley, J., 1991; THE ELEMENTS : Sec. Ed., Clarendon Press, Oxford, 251 p. |