CVD vs HPHT Diamonds: Which Lab-Grown Diamond Should You Choose in 2026?

Choose the diamond for its appearance, documented quality and price—not its growth method alone. Both CVD and HPHT produce real lab-grown diamonds, and either method can produce a beautiful stone.

For buyers exploring jewellery with Glora Diamonds in Chennai and Bangalore, understanding these terms helps you ask better questions before choosing an engagement ring, pendant or other piece.

What Is a CVD Diamond?

CVD stands for Chemical Vapour Deposition. A diamond seed is placed in a chamber containing carbon-rich gas. Under controlled conditions, carbon deposits onto the seed, growing diamond material layer by layer.

Some CVD diamonds undergo treatment after growth to improve their colour. Others are produced without that additional step.

What Is an HPHT Diamond?

HPHT stands for High Pressure High Temperature. This process uses high pressure and temperature to grow diamond from a carbon source around a seed, typically with a metallic flux that assists growth.

HPHT can produce colourless diamonds as well as coloured stones. It is not a method reserved for yellow or blue diamonds.

GIA explains both diamond growth processes.

CVD vs HPHT: A Practical Comparison

Question	CVD diamonds	HPHT diamonds
Are they real diamonds?	Yes	Yes
How are they grown?	Carbon deposits from gas onto a seed	Carbon crystallises around a seed under high pressure and temperature
Can they be colourless?	Yes	Yes
Is high clarity guaranteed?	No—check the individual stone	No—check the individual stone
Is one always cheaper?	Compare actual quotations	Compare actual quotations
What should guide your choice?	Appearance, report, dimensions and price	Appearance, report, dimensions and price

Growth characteristics can differ, but the method’s name is not a quality grade.

CVD Growth and HPHT Treatment Are Different Things

A diamond can be CVD-grown and subsequently HPHT-treated.

In that case, CVD describes how the diamond was created. HPHT describes a later treatment used to modify its colour. Treatment does not change its original growth method.

GIA’s research documents post-growth HPHT processing in CVD diamonds and explains that treatment and growth are separate processes. Read GIA’s laboratory-grown diamond research summary.

Ask what the applicable report records rather than assuming “CVD” means untreated.

How Should You Compare Two Diamonds?

1. Compare Their Appearance

View the actual stones where possible, or request clear videos. Look at their colour, visible inclusions and how they handle light.

Compare similar shapes under similar lighting. Neither growth method guarantees greater sparkle.

2. Check Dimensions Alongside Carat Weight

Carat measures weight. Two diamonds of similar weight can have different proportions and face-up dimensions.

For a ring, consider how the stone looks on your hand and whether the setting suits your routine.

3. Read the Applicable Report

Confirm laboratory-grown origin, measurements and the recorded quality assessments.

Report formats vary. IGI states that growth process and treatment information can be noted upon request, so those details are not necessarily included on every report. Explore IGI’s laboratory-grown diamond report guidance.

4. Compare the Complete Quotation

For finished jewellery, confirm the selected diamond, gold purity, metal weight, making charges and taxes.

A lower ring price may reflect differences in the stone or setting rather than the growth method.

Choosing Your Diamond with Glora

Start with Glora’s engagement rings or pendant collection. Ask about the documentation and specifications of the particular piece you are considering.

For a personal design, explore our custom jewellery service. If you prefer a particular growth method, mention it during the consultation so availability can be confirmed.

Chennai: Visit Glora Diamonds at 31, Govindu Street, North Usman Road, T. Nagar, Chennai, Tamil Nadu 600017.

Bangalore: See our Bangalore page and contact the team for current Dickenson Road showroom and appointment details.

Contact Glora Diamonds to discuss your diamond options →