Properties of Iridium (Ir)
Iridium is a chemical element with the symbol (Ir) and atomic number 77. It belongs to the platinum group of elements and is a dense, corrosion-resistant metal. Iridium is known for its extreme hardness and high melting point, making it useful in various industrial applications.
The following table provides a comprehensive list of iridium (Ir) properties in both SI and US customary/Imperial units at normal temperature and pressure (NTP).
Click on the icon to switch between Metric and Imperial units.
| Physical Properties | Metric |
|---|---|
| Crystal Structure | Face-centered cubic (fcc) |
| Atomic Number | 77 |
| Molar Mass | 192.217 g/mol |
| Density | 22560 kg/m3 |
| Mechanical Properties | Metric |
| Young’s Modulus (E) | 528 GPa |
| Shear Modulus (G) | 209 GPa |
| Bulk Modulus (K) | 387.6 GPa |
| Poisson’s Ratio (ν) | 0.262 |
| Mohs Hardness | 6.5 |
| Thermal Properties | Metric |
| Melting Point | 2446 °C |
| Boiling Point | 4130 °C |
| Thermal Conductivity (27°C) | 147 W/m·K |
| Specific Heat Capacity (Cp) (25°C) | 130 J/kg·K |
| Coefficient of Thermal Expansion (αL) (25°C) | 6.4×10-6 1/°C |
| Electrical Properties | Metric |
| Electrical Resistivity | 4.7×10-6 Ω·cm |
Unless stated otherwise, all values are taken at room temperature (approximately 20°C or 68°F) and 1 atm pressure. (1 atm = 101,325 Pa)
Related Pages
References: 1) Cardarelli, François. Materials Handbook: A Concise Desktop Reference. Switzerland: Springer International Publishing, 2018. 2) CRC Handbook of Chemistry and Physics, 97th Edition. United Kingdom: CRC Press, 2016-2017. 3) A.M. Howatson, P.G. Lun, J.D. Todd, P.D. Engineering Tables and Data. United Kingdom: University of Oxford, Department of Engineering Science, 2009.