Diamond is far more than a precious stone. It is one of the most extraordinary materials nature has produced — and that science has managed to reproduce. Its physical and chemical properties make it a material without equal, as precious for the high-technology industry as for fine jewellery.
Composition
A diamond is composed of pure carbon atoms arranged in a rigid cubic crystal lattice. This structure — known as the diamond lattice — is responsible for almost all of its remarkable properties.
Hardness: 10/10 on the Mohs Scale
Diamond is the hardest naturally occurring material known. It achieves the maximum score of 10 on the Mohs scale. This extreme hardness derives from the strength of the covalent bonds between carbon atoms — among the strongest that exist in chemistry. A diamond can only be scratched by another diamond.
Refractive Index
Diamond's refractive index (2.42) is exceptionally high. This means that light slows considerably upon entering the stone and bends sharply. This is what creates the characteristic brilliance — what gemmologists call "brilliance" — unique to diamond.
Dispersion: Diamond's Fire
Dispersion refers to a material's ability to decompose white light into its constituent colours. Diamond has a high dispersion (0.044), creating flashes of rainbow-like colours known as "fire". It is this fire that makes diamond so spectacular under direct light.
Transparency
High-quality diamonds are perfectly transparent across a wide range of the light spectrum, including in ultraviolet. This exceptional transparency is one of the reasons diamond is used in precision optical instruments.
Thermal Conductivity
Diamond is the best natural thermal conductor known — far superior to copper or silver. This property, exploited in the electronics industry, also explains why a diamond feels "cold" to the initial touch.
Natural and Lab-Grown Diamond: Identical Properties
Lab-grown diamonds created by CVD or HPHT share exactly these same physical and chemical properties. A gemmologist can only distinguish them using specialised equipment. To the naked eye, to the touch, under spectroscopic analysis — they are diamonds, in every sense of the word.