Boron suboxide is a chemical compound with the formula B6O. It is also known by other names, such as boron oxide, diboron trioxide, and boron sesquioxide. The molecular structure of boron suboxide is composed of six boron atoms and one oxygen atom.

Boron suboxide is a solid material that exists in various phases and crystal structures, depending on the preparation method and conditions. The compound can be found in the form of dark brown crystals or as an amorphous powder.

One of the most well-known properties of boron suboxide is its exceptional hardness. It is considered one of the hardest known materials, with a hardness value close to that of diamond. This makes boron suboxide a potential candidate for applications in cutting tools, wear-resistant coatings, and other materials that require high hardness and toughness.

Boron suboxide also possesses interesting electronic properties, such as being a wide-bandgap semiconductor. As a result, it has been studied for its potential applications in electronic devices and optoelectronics.

Additionally, boron suboxide exhibits good thermal stability and chemical resistance, making it useful in high-temperature environments and as a refractory material.

Like with any chemical compound, handling boron suboxide should be done with proper safety precautions, and its potential uses and properties are subject to ongoing research and development in the field of materials science and engineering.