It’s time to get down to the nitty gritty. What on earth is a diamond anyway? What are they made of? and, How does diamond formation happen? These questions are often overlooked and replaced with one simple question, “How much does it cost?” But let’s set that one aside for now and get down to a little geological science 101. If you were too busy at school to pay attention in science class, now’s your time to catch up on all the knowledge lost.
How does diamond formation happen?
First of all, diamonds are old. I don’t mean old like your grandma. I mean really really old. For a diamond to form it takes about 1 billion to 3.3 billion years. Natural diamonds are formed at extremely high temperatures and under severe pressure, deep near the earth’s core. When I say deep, I mean between 140 to 190 kilometres deep in the ground (that’s between 87 to 118 miles deep). That’s deep. The diamond doesn’t just form out of nothing of course. There needs to be some kind of carbon source like a mineral that contains carbon for example. When this mineral undergoes that kind of pressure and heat, it will eventually form a diamond.
Essentially, diamonds are pure carbon subjected to crushing pressure and molten heat. Eventually these diamonds are pushed up to the surface, where they are mined several million years later. Most of the diamonds mined today are at least 25% to 75% the age of the earth itself.
Diamond and graphite are two differing forms of carbon. Though similar, diamonds formation is far rarer than graphite formation. Boiling it down to the basic science, a diamond is a transparent crystal of tetrahedrally (like a pyramid) bonded carbon atoms in a shared network lattice, which then crystallizes into the famous diamond lattice.
Of course, not all diamonds are formed under ground these days. Thanks to the wonders of science and technology, many diamonds are now produced in laboratories. These are known as synthetic diamonds. There are two common production methods. HPHT (which stand for high-pressure high-temperature) or CVD (which stands for chemical vapor deposition). These diamonds often sell for 20-30% less than mined diamonds although they share the same physical and chemical properties as mined diamonds.