Osmium
Real Metals · Very Rare · Modern
The densest element in the periodic table, osmium is so rare that the entire world's annual production would fit in a coffee cup. Its extreme density makes a block of osmium feel almost unreal, far heavier than the eye expects.
Identity
- Symbol
- Os
- Atomic number
- 76
- Source
- Natural element
- Also known as
- Os
- Ores of the industrial age
- Osmiridium, Osmium, Pentlandite, Platinum
- Ore deposits
- Placer deposit
Physical Properties
- Appearance
- Blue-grey, hard, brittle; the densest naturally occurring element known
- Luster
- Metallic
- Density
- 22.59 g/cm³
- Melting point
- 3033 °C
- Boiling point
- 5012 °C
- Lighter
- Iridium
- Magnetism
- Non-magnetic
- Electrical conductivity
- Medium
Mechanical Properties
- Mohs hardness
- 7
- Tensile strength
- 500 MPa
- Softer
- Vanadium
- Harder
- Tungsten
- Workability
- Difficult
- Brittleness
- Brittle
- Malleability
- Very Low
- Ductility
- Very Low
Chemical Properties
- Corrosion resistance
- Very High
- Reactivity
- Low
Lore & Narrative
Its name comes from the Greek osme, 'smell', because osmium tetroxide, produced when osmium oxidizes, has a distinctive acrid odor. This compound is also severely toxic, making osmium uniquely dangerous in powdered or oxidizing forms.
- Notable uses
- Pen tips, compass needles, electrical contacts, scientific instruments
- Forge uses
- Precision instruments, Electrical contacts
- Worldbuilding traits
- Densest, Rare, Toxic-oxide, Extreme
Sources
- U.S. Geological Survey, Mineral Commodity Summaries 2025: Platinum-Group Metals, USGS, 2025
- Osmium, Wikipedia
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