CVD vs HPHT: The Two Ways to Grow a Diamond

Every lab grown diamond is made by one of two methods: CVD (Chemical Vapour Deposition) or HPHT (High Pressure, High Temperature). Both produce real diamond. They simply take different routes to get there.

HPHT: recreating the earth

HPHT copies the conditions deep underground where natural diamonds form. A small diamond seed is placed in a press with a source of carbon and a metal catalyst, then subjected to enormous pressure and temperatures well above 1,000°C. The carbon melts into the catalyst and crystallises onto the seed, growing a rough diamond.

CVD: building atom by atom

CVD works at low pressure. Thin diamond seed plates sit inside a sealed chamber filled with a carefully balanced mix of hydrogen and a carbon-rich gas such as methane. Microwave energy turns the gas into a glowing plasma, and carbon atoms settle onto the seeds layer by layer over several weeks. The diamonds in our collection are grown this way.

Does the method change the diamond?

Not in any way you can see. Both methods produce diamond with the same hardness, brilliance and fire. Some stones receive a post-growth treatment to refine their colour, which is standard practice and noted on the grading report. What matters for beauty is the same as for any diamond: cut, colour, clarity and carat.

What to look for

• An independent grading report from a recognised laboratory such as IGI.
• Colour and clarity grades you are comfortable with. Every stone in our collection is E–F colour and VVS–VS clarity.
• Solid gold, so the setting lasts as long as the diamond.

Keep reading: From Seed to Sparkle: How a Lab Grown Diamond Is Made

Lab grown diamond jewellery in solid 14K gold, prices inclusive of GST, with free shipping across New Zealand and Australia. Shop the collection on KlōT͟HiNG →