CVD & HPHT Diamond Guide

CVD and HPHT are two methods used to grow laboratory-grown diamonds. Understanding the methods helps you read a stone’s documentation and ask useful questions.

CVD: chemical vapour deposition

In a controlled chamber, carbon from a gas is deposited onto a diamond seed, allowing the crystal to grow in layers.

HPHT: high pressure, high temperature

This method uses high pressure and high temperature to grow diamond crystals from a carbon source.

Choose the individual stone

The growth method alone does not tell you how attractive a diamond will look in your jewellery. Compare the stone’s appearance, measurements and available laboratory documentation alongside the setting you prefer.

Before you decide

• Confirm whether the stone is natural or laboratory-grown.
• Ask about the growth method and any disclosed treatment.
• Check which report, if any, accompanies your selected option.

Read more in GIA’s explanation of HPHT and CVD growth, or return to our Diamond Guide.

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