Diamond, Properties and More

Diamond is considered the hardest natural substance found on Earth. Though it is not the hardest substance. Lonsdaleite, for example, is harder, but it is found only in meteorites.

Diamonds are generally insensitive to chemical reactions, though high temperatures can damage their surface. Because of this it is necessary to take care when soldering. And yes, they will burn at sufficiently high temperatures and with a good supply of oxygen. After all, they are just crystallised carbon.

Diamonds perfect cleavage makes it susceptible to damage should the edge be struck, and care must be taken when setting a stone. You have surely heard of cutters splitting a rough diamond with a well placed tap of a hammer.

Origin of Name

The name ‘diamond’ is derived from the Greek word adamas, meaning the unconquerable. This is obviously a reference to its hardness.


Diamonds are found in many countries across the world, though the number of commercial mines is limited. The following is a list of some continents and countries with commercial mines.

  • Africa – Angola, Botswana, Democratic Republic of the Congo, Ghana, Guinea, Lesotho, Namibia, Sierra Leone, South Africa, Tanzania, and Zimbabwe.
  • Asia – India, Indonesia and Russia.
  • North America – Canada and the United States of America.
  • Oceania – Australia.
  • South America – Brazil and Guyana.


The properties we have listed are by no means complete. We have listed only those we believe will be useful to jewellery makers. However, if you feel we need to add more please contact us and let us know.

Property Value
Colour: Colourless, yellow, brown, green, blue, red, pink
Colour of Streak: White
Lustre: Adamantine
Moh’s Hardness: 10
Density: 3.50 – 3.53
Crystal: Cubic
Crystal Class Hexaoctohedral
Cleavage: Perfect
Fracture: Conchoidal to splintery
Chemical Composition: C, carbon
Transparency: Transparent to opaque
Refractive Index: 2.417 – 2.419
Double Refraction: None
Dispersion: 0.044 (0.025)
Pleochroism: None

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