What Is a Diamond?
Diamonds are the hardest known natural material, composed of pure carbon atoms arranged in a crystal structure known as the diamond cubic lattice. This unique arrangement provides diamonds with unparalleled hardness, making them capable of scratching other substances, including other diamonds. Diamonds are celebrated for their brilliance, which is the result of their high refractive index and dispersion.
How Are Diamonds Made?
Natural Diamonds
Natural diamonds form deep within the Earth's mantle, about 80-120 miles below the surface, under extreme pressure and temperature conditions. Over billions of years, carbon crystallizes into diamonds and is eventually brought to the surface through volcanic eruptions. Natural diamonds vary in colour, size, and clarity due to the different minerals and conditions present during their formation. For instance, nitrogen gives diamonds a yellow hue, while boron imparts a blue colour.
Lab-Grown Diamonds
Lab-grown diamonds are produced in controlled environments that replicate the conditions of natural diamond formation. They are not 'fake' or 'synthetic' but have the same chemical composition, crystal structure, and properties as natural diamonds. There are two primary methods:
High Pressure, High Temperature (HPHT): Mimics the high-pressure, high-temperature conditions of natural diamond formation. HPHT diamonds are created at pressures of 5–6 GPa and temperatures of 1300–1600°C.
Chemical Vapor Deposition (CVD): Uses moderate temperatures (700°C to 1300°C) and lower pressures. Carbon-containing gas is introduced into a vacuum chamber, where it crystallizes on a diamond seed to form the diamond.
The Difference Between Natural and Lab-Grown Diamonds
Inclusions
Both natural and lab-grown diamonds can have inclusions, which are imperfections within the diamond. Natural diamonds often include inclusions from the minerals and conditions experienced during their formation. Lab-grown diamonds may have metallic inclusions due to the manufacturing process. While these inclusions are not visible to the naked eye, trained gemmologists can distinguish between them using magnification.
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Diamond Alternatives
When researching diamonds, you may come across terms like 'synthetic' or 'simulant' diamonds. These differ from both natural and lab-grown diamonds as they have distinct chemical and physical properties. While they may resemble diamonds, they do not match the durability and brilliance of genuine diamonds. Some common diamond alternatives include:
Moissanite: A naturally occurring mineral with similar brilliance but less hardness than diamonds.
Cubic Zirconia: A synthetic gemstone that is a popular, budget-friendly alternative but lacks the durability of diamonds.
White Sapphire: A natural gemstone that can mimic the appearance of diamonds but is less hard and less brilliant.