Osmium has a blue-gray tint and is the densest stable element; it is approximately twice as dense as lead and slightly denser than iridium.
Calculations of density from the X-ray diffraction data may produce the most reliable data for these elements, giving a value of 22.587±0.009 g/cm³ for osmium, slightly denser than the 22.562±0.009 g/cm³ of iridium; both metals are nearly 23 times as dense as water, and ​1 ¹⁄₆ times as dense as gold.

Osmium is a hard but brittle metal that remains lustrous even at high temperatures.
It has a very low compressibility.
Correspondingly, its bulk modulus is extremely high, reported between 395 and 462 GPa, which rivals that of diamond (443 GPa).
The hardness of osmium is moderately high at 4 GPa.
Because of its hardness, brittleness, low vapor pressure (the lowest of the platinum-group metals), and very high melting point (the third highest of all elements, after only tungsten, and rhenium), solid osmium is difficult to machine, form, or work.
Osmium has a blue-gray tint and is the densest stable element; it is approximately twice as dense as lead and slightly denser than iridium. Calculations of density from the X-ray diffraction data may produce the most reliable data for these elements, giving a value of 22.587±0.009 g/cm³ for osmium, slightly denser than the 22.562±0.009 g/cm³ of iridium; both metals are nearly 23 times as dense as water, and ​1 ¹⁄₆ times as dense as gold. 
Osmium is a hard but brittle metal that remains lustrous even at high temperatures. It has a very low compressibility. Correspondingly, its bulk modulus is extremely high, reported between 395 and 462 GPa, which rivals that of diamond (443 GPa). The hardness of osmium is moderately high at 4 GPa. Because of its hardness, brittleness, low vapor pressure (the lowest of the platinum-group metals), and very high melting point (the third highest of all elements, after only tungsten, and rhenium), solid osmium is difficult to machine, form, or work.
Osmium