Lab grown diamonds are made by turning carbon into diamond crystal in a controlled laboratory setting. The two main methods are high pressure high temperature, or HPHT, and chemical vapor deposition, or CVD. Both methods produce real diamonds with the same crystal structure as mined diamonds.
For buyers, the key point is simple: a lab grown diamond is still a diamond. What changes is the growth environment, not the basic material. If you want a broader foundation before comparing manufacturing methods, see what a lab grown diamond is.
What lab grown diamonds are made from
Lab grown diamonds are made from carbon. In both HPHT and CVD growth, technicians start with a diamond seed, which is a thin slice of existing diamond crystal, and then add carbon in conditions that allow more diamond crystal to form on that seed.
Because the crystal that forms is diamond, the result has the same chemical composition as a natural diamond. The main difference is origin: one formed underground over geologic time, while the other formed in a lab over weeks or months.
The two main methods: HPHT and CVD
The two standard manufacturing methods are HPHT and CVD. These terms also appear in product descriptions for loose lab grown diamonds such as the 13.06ct IGI Lab Diamond and the 4.11CT Pink Pear Lab Diamond, which identify CVD and HPHT as recognized growth methods in the lab grown diamond market.
HPHT in simple terms
HPHT stands for high pressure high temperature. This method recreates the extreme pressure and heat conditions under which diamonds form naturally deep within the Earth. A small diamond seed is placed with a carbon source inside specialized equipment, and intense pressure and temperature help the carbon crystallize into diamond.
CVD in simple terms
CVD stands for chemical vapor deposition. In this method, a diamond seed is placed in a chamber filled with carbon-rich gas. The gas is energized so carbon atoms separate and attach to the seed layer by layer, gradually growing a larger diamond crystal.
How HPHT lab grown diamonds are made step by step
A small diamond seed is prepared and placed into growth equipment.
A carbon source is added.
The machine applies very high pressure and very high temperature.
Carbon melts or dissolves into the growth environment and then bonds to the seed as diamond crystal.
The rough diamond is cooled, removed, and later cut and polished.
HPHT is often described as a process that imitates natural underground formation conditions. It can also be used in some cases after growth to influence color or clarity characteristics in certain diamonds, which is why grading reports matter when you want precise origin and treatment details.
How CVD lab grown diamonds are made step by step
A thin diamond seed plate is placed inside a sealed chamber.
Carbon-rich gas, often methane mixed with other gases, is introduced.
Heat or microwave energy breaks the gas molecules apart.
Free carbon atoms attach to the seed and build diamond crystal layer by layer.
The rough diamond is removed and may go through additional finishing steps before cutting and polishing.
CVD is often associated with precise crystal growth control because the diamond builds in visible layers. Some lab grown diamonds described by the store are specifically labeled as CVD, such as the IGI CVD Lab Grown Diamonds.
What happens after the diamond is grown
Once a lab grown diamond crystal is produced, it still needs post-growth work before it becomes jewelry-ready. The rough stone is examined, cut into the intended shape, polished, and then graded for qualities such as cut, color, clarity, and carat weight.
Many stones are also sent for independent certification. The store's catalog repeatedly references IGI-certified lab grown diamonds, including loose stones and finished jewelry, and also links to IGI certified lab grown diamonds explained for readers who want more detail on grading documentation.
Are HPHT and CVD diamonds real diamonds?
Yes. HPHT and CVD diamonds are real diamonds because they are crystallized carbon with the same essential material structure as natural diamonds. They are not diamond simulants like cubic zirconia or moissanite.
The meaningful distinction is not whether they are real, but how they were grown and how they are graded. For a buyer comparing origin, pricing logic, and practical tradeoffs, lab grown diamonds vs natural diamonds is the more useful next step.
HPHT vs CVD: what matters to buyers
| Factor | HPHT | CVD |
|---|---|---|
| Growth approach | Uses extreme pressure and heat | Uses carbon-rich gas in a chamber |
| How crystal forms | Carbon crystallizes under compressed, heated conditions | Carbon deposits layer by layer on a seed |
| Common use | Loose stones and some color applications | Loose stones and a wide range of jewelry production |
| Buyer priority | Check grading report for growth and any treatment details | Check grading report for growth and any treatment details |
For most buyers, the growth method matters less than the finished diamond's cut quality, certification, and whether the seller clearly discloses origin and any post-growth treatment. A well-cut, well-graded diamond from either process can be suitable for rings, necklaces, and other fine jewelry.
Why certification matters when buying lab grown diamonds
Certification helps verify that the stone is a lab grown diamond and records measurable quality factors. It can also note information about growth method and any detectable treatments, depending on the lab and the individual stone.
This is especially useful when comparing larger or higher-value stones, such as the 2ct IGI Cushion Lab Diamond or the 10CT IGI Oval Lab Diamond, both of which are presented with IGI certification in the store file.
FAQ
How long does it take to make a lab grown diamond?
It usually takes weeks to months, depending on the size of the diamond, the growth method, and the production target.
Do lab grown diamonds start from a real diamond?
They usually start from a diamond seed, which is a small piece of diamond crystal used as the base for further growth.
Can you tell whether a diamond was made by HPHT or CVD just by looking at it?
Not reliably. Growth method is typically identified through gemological testing and grading documentation rather than normal visual inspection.
Are lab grown diamonds used only for loose stones?
No. They are also used in finished jewelry, including rings, necklaces, bracelets, and earrings, as shown across the store catalog.