10. Tantalum
Chemical element with the symbol Ta and atomic number 73.
- density: 16,650 kg/m³
- discovery: Ekeberg (1802)
- atomic mass: 180,947 u
- Mohs hardness: 6.5
9. Uranium
The chemical element with the symbol U and atomic number 92.
- density: 19,050 kg/m³
- discovery: Klaproth (1789)
- atomic mass: 238,028 u
- Mohs hardness: 4.5
8. Tungsten
Chemical element with the symbol W and atomic number 74.

fot. Cccucumber / wikipedia.org (CC BY-SA 4.0)
- density: 19,250 kg/m³
- discovery: Brothers de Elhuyar (1783)
- atomic mass: 183,84 u
- Mohs hardness: 7.5
7. Gold
The chemical element with the symbol Au and atomic number 79.
- density: 19,300 kg/m³
- discovery: prehistory
- atomic mass: 196,966 u
- Mohs hardness: 2.5
6. Plutonium
A radioactive chemical element with the symbol Pu and atomic number 94.
- density: 19,816 kg/m³
- discovery: Glenn Theodore Seaborg (1941)
- atomic mass: 244,0642 u
- Mohs hardness: ???
5. Neptunium
Chemical element from the actinide group, atomic number 93.
- density: 20,200 kg/m³
- discovery: McMillan and Abelson (1940)
- atomic mass: 237,0482 u
- Mohs hardness: ???
4. Rhenium
The chemical element with the symbol Re and atomic number 75.
- density: 21,020 kg/m³
- discovery: Walter Noddack, Ida Tacke, and Otto Berg (1925)
- atomic mass: 186,207 u
- Mohs hardness: 7
3. Platinum
The chemical element with the symbol Pt and atomic number 78.

fot. Periodictableru / wikipedia.org (CC BY-SA 3.0)
- density: 21,090 kg/m³
- discovery: Scaliger (1557)
- atomic mass: 195,084 u
- Mohs hardness: 3.5
2. Iridium
The chemical element with the symbol Ir and atomic number 77.
- density: 22,420 kg/m³
- discovery: Smithson Tennant (1803)
- atomic mass: 192,217 u
- Mohs hardness: 6.5
1. Osmium
A chemical element from the ferrous metal group with the symbol Os and atomic number 76.

fot. Periodictableru / wikipedia.org (CC BY-SA 3.0)
- density: 22,590 kg/m³
- discovery: Smithson Tennant and William Hyde Wollaston (1803)
- atomic mass: 190,23 u
- Mohs hardness: 7
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