You might calculate volume using the sphere’s radius, circumference or diameter. You can also submerge the sphere in water to find its volume by displacement. Once you know the volume, you can multiply by the density to find the mass.

Pound for pound, diamonds are not very good at stopping bullets. The energy absorbed by diamond shattering is much less than the energy absorbed by metals deforming. A plate of steel would be better at stopping bullets than a plate of diamond. “People mix between hardness and toughness.

Osmium tetroxide is highly volatile and penetrates skin readily, and is very toxic by inhalation, ingestion, and skin contact.

Researchers from us-based Lawrence Livermore National Laboratory (llnl) have discovered that osmium, a metal, is harder than diamond. It withstands compression better than any other material. It is usually found that materials with higher bulk modulus are also hard.

Chemical dangers: The substance decomposes on heating producing fumes of osmium. The substance is a strong oxidant and reacts with combustible and reducing materials. Reacts with hydrochloric acid to form toxic chlorine gas. The substance is corrosive to the eyes, the skin, and the respiratory tract.

Osmium tetroxide is expensive because osmium is a rare element. Osmium is one of the rarest elements in the Earth’s crust. Osmium is obtained as a by-product from nickel and copper processing. The US production of Os is probably only about 75 kg/year.

One gram of osmium converted to pound equals to 0.0022 lb.

Osmium has only a few uses. It is used to produce very hard alloys for fountain pen tips, instrument pivots, needles and electrical contacts. It is also used in the chemical industry as a catalyst. Osmium has no known biological role.

The 4 Strongest and Hardest Metals on Earth

1. Tungsten: The Strongest Metal on Earth. Of all the metals, tungsten reigns supreme in terms of tensile strength.
2. Chromium: The Hardest Metal on Earth. Chromium is the hardest metal known to man.
3. Steel: The Strongest Alloy on Earth.
4. Titanium.