Is it possible to break a Diamond?
In short, the answer is yes. Diamonds belong to the cubic crystal system and have something called 'perfect cleavage', this means that when they fracture along a plane the break will usually be very clean and flat. This is not always the case when you chip one though, you can also get conchoidal fracture which can look like a piece of fractured glass. So with diamonds set in jewellery, a hard enough blow to the stone in the wrong direction could fracture it or worse. Diamonds are incredibly hard, so it is unlikely that through normal wear you will break a stone.
Saying that, some types are diamond are more likely to break than others. Black diamonds for instance (and lower clarity grades such as (I) Included 2-3) are more likely to break or fracture as the inclusions create weak points within the stone. Consider investing in a stone that is VS2 or above, not only will the inclusion be so small it is not visible to the naked eye, the diamond is less likely to ever become damaged through wear.
Diamonds are commonly thought of as the hardest material known, so how are they cut? Diamonds have to be cut against one another by using their directional hardness. Diamonds have four areas of hardness, the softest of which is across the octahedral plane. The hardest of which is which is diagonally on the cubic plane. By exploiting the hardest plane against the weakest plane it is possible to facet the stone. Diamond is 10 on MOH's scale of hardness (defined as the ability to scratch another material), where Synthetic Moissanite is 9.5 and Sapphire/Ruby (Corundum) is 9.
If you are looking for advice regarding purchasing a diamond contact me to discuss your requirements.
An Indent Natural pictured on this stone is part of the original rough material of the stone and can look like a chip or fracture