CVD vs HPHT Lab Diamonds: What Singapore Buyers Should Know

Lab grown diamonds are produced by two distinct processes — CVD (Chemical Vapour Deposition) and HPHT (High Pressure High Temperature). Both produce real diamonds. Both are graded on the same 4Cs scale by the same laboratories. But they differ in how they are grown, what characteristics they tend to produce, and what to look for when evaluating a specific stone.

At Diamond Ateliers, we source lab grown diamonds for bespoke commissions every week. This guide explains the practical differences between CVD and HPHT in clear terms — not to push you toward one or the other, but so you can ask the right questions and understand what you are looking at.

How HPHT Diamonds Are Grown

HPHT replicates the conditions deep within the earth — extreme heat and pressure — to grow a diamond from a carbon seed. The metal catalyst used in HPHT growth can become incorporated into the diamond as small metallic inclusions. Well-grown HPHT diamonds at VS clarity and above have inclusions that are not visible to the naked eye.

How CVD Diamonds Are Grown

CVD grows diamonds in a controlled plasma environment. Because CVD uses no metal catalyst, CVD diamonds do not have the metallic inclusions associated with HPHT growth. CVD diamonds can occasionally show a slight brown or greyish tint, particularly in larger stones. Most of the lab grown diamonds we recommend at Diamond Ateliers are CVD-grown.

Does the Growth Method Affect Beauty?

Not directly. A well-cut CVD diamond and a well-cut HPHT diamond of equivalent grades will look the same to the naked eye. The growth method affects the type of inclusions present and the likelihood of certain colour tendencies — it does not determine brilliance, fire, or scintillation. Those are determined by cut quality.

How to Choose

For most buyers in Singapore looking for a colourless engagement ring diamond, CVD is the default for good reason. HPHT makes more sense when you are specifically interested in fancy coloured lab grown diamonds.

In both cases, the certificate should state the growth method. If it does not, ask. A reputable jeweller will know exactly how every stone in their inventory was grown.

Book a consultation to compare CVD and HPHT stones in person, or message us on WhatsApp with any questions.