CVD Diamonds Explained Clearly
CVD Diamonds explained clearly
CVD is one of the most important methods for producing modern lab-grown Diamonds.
But what happens in the reaction chamber, what role does plasma play, and what does the designation CVD actually say about a finished Diamond?
What does CVD mean?
CVD stands for Chemical Vapor Deposition.
In this process, a Diamond crystal grows on a small Diamond seed in a controlled reaction chamber. Carbon-containing gases provide the carbon from which the growing Diamond structure is built.
What role does plasma play?
The Diamond seed is placed in a controlled chamber. It contains a gas atmosphere that includes, among other things, carbon-containing components.
Energy input creates an activated plasma environment. This enables chemical reactions through which carbon can be deposited on the surface of the Diamond seed.
- Diamond seed as the growth base
- controlled gas atmosphere
- activated plasma
- Carbon as building material
- controlled crystal growth
The Diamond grows layer by layer
In the CVD process, carbon atoms attach to the existing Diamond structure.
The crystal gradually continues growing on the Diamond seed. This process continues under controlled conditions until a sufficiently large rough crystal has formed.
This is what a CVD rough crystal looks like
After growth, it is not yet a finished jewelry diamond.
The CVD rough crystal may have a different external shape from the stone that is later cut. Only through careful planning, cutting, faceting, and polishing does it become, for example, a Round Brilliant, Oval, Pear, or Emerald Cut.
Do CVD Diamonds have special characteristics?
The controlled formation can leave growth characteristics that are recognizable through gemological examination. These are analyzed using professional examination methods and help specialist laboratories determine the origin.
Such growth characteristics are not automatically equivalent to a visible impairment for the buyer. The decisive factor is always the specific quality of the finished, cut Diamond.
Growth
The crystal structure forms under controlled CVD conditions.
Processing
The rough crystal is planned, cut, faceted, and polished.
Examination
The finished Diamond can then be examined and graded gemologically.
What does post-growth treatment mean?
For certain CVD Diamonds, additional technical processes may be used after the actual growth phase.
Such so-called Post-Growth Treatments can, for example, be used to alter or optimize certain color properties of a Diamond.
Is a CVD Diamond automatically high quality?
No. CVD only describes how the Diamond was grown.
As with other Diamonds, individual CVD stones can differ considerably in size, color, clarity, proportions, and cut quality.
The 4Cs
- Carat – Weight
- Cut – Cut
- Color – Color
- Clarity – Clarity
In addition
- Actual measurements
- Proportions
- Polish
- Symmetry
- Overall appearance
What does the laboratory report say?
An independent gemmological report helps document a diamond’s characteristics and origin in a verifiable way.
Depending on the report, the following information may be included, among other details:
- Laboratory origin
- Growth method
- Carat weight and measurements
- Color and clarity
- Cut characteristics
- Polish and symmetry
- Notes on identified post-growth treatments
- Laser inscription or additional comments
What should I look for in a CVD diamond?
Examine the cut
The finished diamond’s light performance is more important than the name of the growth method.
Compare the 4Cs
Weight, color, and clarity should be considered together with the proportions.
Read the report
Check the origin, growth method, and any additional information provided.
“CVD is always better than HPHT.”
This cannot be stated in general terms.
CVD and HPHT are different growth methods. A high-quality diamond can be produced using either method. For buyers, the quality and appearance of the specific diamond should be the focus.
CVD diamonds at a glance
- CVD stands for Chemical Vapor Deposition.
- Growth begins on a diamond seed.
- An activated plasma environment enables carbon deposition.
- The diamond grows gradually as a crystal.
- After growth, a rough crystal is formed first.
- It is then cut and polished.
- Post-growth treatments are possible, but are not automatically present.
- CVD alone is not a quality grade.
- An independent laboratory report provides additional transparency.
Understand CVD. Compare diamonds more consciously.
Discover more information about how lab-grown diamonds are created, the 4Cs, and independent quality reports.
Discover diamond knowledge How are lab-grown diamonds created? Diamond certificate