CVD Diamonds

CVD Diamonds

CVD diamonds, crafted through Chemical Vapor Deposition, mirror natural diamonds in their characteristics while being synthesized in a laboratory setting. Discover the process behind their creation, explore their distinctions from both natural and other lab-produced diamonds, and determine whether a CVD diamond aligns with your preferences.

What is a CVD diamond?

Chemical Vapor Deposition, commonly abbreviated as CVD, refers to the process of cultivating diamonds in a laboratory through chemical vapor deposition. This technique differs from another prevalent method used for creating lab-grown diamonds known as HPHT (High Pressure High Temperature).

CVD diamonds, though human-made, are indistinguishable from natural diamonds, constituting 100% authentic diamonds. Indeed, without specialized equipment, discerning a CVD diamond from a natural one is impossible. Delve deeper into the distinctions between lab diamonds and their natural counterparts.

The allure of lab diamonds is steadily increasing among buyers of engagement rings and jewelry. Both CVD and HPHT methods stand as two of the most widely employed production approaches. CVD diamond jewelry offers several advantages, including ethical origins, sustainability, and relatively lower prices—although it’s worth noting that CVD diamonds typically exhibit lower quality compared to HPHT diamonds. As the demand for CVD diamonds rises, Queensmith’s gemmologists possess specialized expertise in sourcing and curating exquisite CVD diamonds, ensuring optimal value for money.

Properties of a CVD diamond

CVD diamonds exhibit identical properties to natural diamonds, boasting the same internal structure, chemical composition, and captivating physical allure. Similar to natural diamonds, CVD diamonds possess exceptional durability, scoring a perfect 10 on the Mohs scale of hardness, and exude remarkable brilliance and sparkle.

However, distinguishing between a lab-created CVD diamond and a natural diamond of equivalent quality is virtually impossible. It’s important to note that CVD diamonds often display less desirable characteristics such as brown tints and internal graining, frequently necessitating post-growth treatment. In comparison, HPHT lab-created diamonds typically boast superior quality when contrasted with CVD diamonds.

CVD diamonds undergo grading for cut, color, clarity, and carat weight, akin to natural diamonds. Despite being human-engineered, CVD diamonds are susceptible to similar imperfections as their natural counterparts, potentially acquiring color tints and internal flaws during their growth. Discovering completely flawless CVD diamonds is exceedingly rare—some might exhibit significant inclusions and unfavorable coloration, while others may appear entirely colorless with minute imperfections, echoing the traits found in natural diamonds. Aim for clarity grades falling within the range of SI1 to VS1 and color grades from D to F to secure a high-quality appearance and good value for your investment.

The undeniable truth is that even seasoned gemmologists cannot distinguish a CVD diamond from a natural one. This is due to the fact that CVD diamonds are, essentially, diamonds possessing identical chemical, physical, and optical properties, inclusive of identical flaws. Upon purchasing a CVD diamond, its origin will be documented on the GIA or IGI certification. Beyond this certification, specialized laboratory equipment becomes necessary to ascertain that the diamond was artificially created.

Chemical Vapour Deposition (CVD) diamond making process

The process of creating Chemical Vapor Deposition (CVD) diamonds involves a meticulous series of steps:

1. Diamond Seed Selection: A thin diamond seed, usually around 300 microns thick and 10x10mm, is meticulously chosen and cleaned thoroughly. This seed, derived typically from a high-quality diamond produced by HPHT, serves as the foundation for CVD diamond growth.

2. Sealed Chamber Preparation: The cleaned diamond seed is placed in a sealed chamber, which is then heated to approximately 800°C. The chamber is flooded with a carbon-rich gas, ensuring a sealed environment to prevent interference from other gases.

3. Ionization and Growth: Under the high temperature, the carbon-rich gas ionizes, breaking down into pure carbon molecules. These molecules bond with the existing diamond seed, gradually building upon it as more gas ionizes and bonds. This crystallization process persists until a complete, rough diamond is formed.

4. Rapid Growth: CVD diamonds grow relatively swiftly, taking about two to four weeks to reach full development. However, this rapid growth can sometimes result in less desirable traits like graining, spotted inclusions, or brown tints. Post-growth treatments using HPHT methods can improve these imperfections, but this might occasionally cause a milky appearance. It’s advisable to seek out CVD diamonds that haven’t undergone post-growth treatments, usually indicated on the diamond’s certificate.

5. Finishing and Certification: Once created, the CVD diamond undergoes processes similar to those of natural diamonds. It is professionally cut to the desired shape, meticulously polished to enhance its brilliance, and then graded and certified by independent laboratories such as GIA and IGI. These certified diamonds eventually enter the jewelry market through dealers like Queensmith, who meticulously select the best CVD diamonds based on official certification, beauty, and price to present to their clientele.

The CVD diamond-making process involves specialized scientific techniques honed over decades, enabling the production of jewelry-grade diamonds efficiently and with relative speed through adaptation from the semiconductor industry’s chemical vapor deposition method.

How fast do CVD diamonds grow?

The growth rate of a CVD diamond relies on both the desired final size of the stone and the efficacy of the technologies employed. Leading CVD diamond manufacturers have demonstrated the ability to produce 1-carat diamonds in under a month, and slightly smaller diamonds in as little as two weeks. However, the creation of fancy color diamonds, such as yellow CVD diamonds, may take anywhere from 5 to 10 days. The inclusion of nitrogen to achieve the yellow hue accelerates the crystallization process, resulting in this shorter growth period for colored diamonds.

CVD vs HPHT Diamonds

HPHT diamonds, fashioned through the High Pressure High Temperature process, contrast with CVD diamonds produced via Chemical Vapor Deposition.

In the HPHT method, rather than utilizing gas, the process replicates the natural diamond formation occurring under immense pressure and high temperatures within the Earth’s depths, a process that spans millions of years. Like CVD diamonds, HPHT diamonds take a few weeks to develop but demand higher energy levels. Experts commonly observe that HPHT diamonds often exhibit superior quality compared to CVD diamonds and tend to necessitate post-growth treatment less frequently.

The primary distinction between rough CVD and HPHT diamonds lies in their structural formation. CVD diamonds grow in a cubic shape, while HPHT diamonds assume a cuboctahedral form. However, this variance is discernible only to highly trained experts.

Additionally, some laboratories initiate the diamond creation process with the less energy-intensive CVD method before concluding with HPHT treatment. This combined approach harnesses HPHT’s potential to enhance clarity and color. Nonetheless, both CVD and HPHT diamonds remain chemically, physically, and optically identical to natural diamonds.

How do You Identify a CVD Diamond?

Identifying a CVD diamond apart from a natural one is nearly impossible without specialized laboratory equipment and gemmological expertise due to their identical nature. Like natural diamonds, CVD diamonds span a range of qualities and grades, yet comparing two with identical grades won’t reveal any noticeable differences. This similarity is reassuring for CVD diamond buyers concerned about authenticity or differences from natural diamonds.

Under magnification, a CVD diamond might exhibit different strain patterns compared to natural diamonds. However, recognizing these differences requires specialized gemmological knowledge, and even seasoned gemmologists may struggle to discern the variance.

Diamond laboratories utilize equipment to detect minute trace elements like silicon, which may be present in CVD-created diamonds. This process demands highly specialized expertise, and submitting the diamond to a laboratory like GIA is necessary.

When purchasing a CVD diamond, ensure it bears certification from GIA or IGI. The accompanying certificate specifies whether the diamonds are natural or lab-created via CVD or HPHT methods. Crucially, it indicates whether the diamond has undergone post-growth treatment to enhance its appearance. Diamonds subjected to post-growth treatments are advisable to be avoided.

CVD Grading and Certification

CVD diamonds undergo a grading process similar to mined diamonds, evaluating their cut, color, clarity, carat weight, and additional aspects such as fluorescence, polish, and symmetry. Various grading laboratories worldwide certify lab diamonds, with GIA (Gemological Institute of America) and IGI (International Gemological Institute) standing as the most reputable and trusted entities.

Both GIA and IGI meticulously assess CVD diamonds to determine their characteristics, providing an accurate assessment of their quality, thereby influencing the stone’s pricing. These institutions laser imprint a unique code onto the girdle of the diamond, visible only under magnification. This code corresponds to a paper or digital certificate containing comprehensive details about the stone, encompassing its grades, carat weight, measurements, and crucially, confirming whether the diamond was created by CVD, HPHT, or is a natural diamond.

At Queensmith, our recommendation aligns with acquiring lab diamonds certified exclusively by GIA and IGI. Each diamond within our inventory undergoes thorough vetting and selection by our gemmologists, ensuring a blend of value and exquisite aesthetics. We solely procure GIA-certified diamonds and IGI-certified diamonds, prioritizing trust and quality for our clientele.

How Much do CVD lab Diamonds Cost?

CVD diamonds often come with a notably lower price tag compared to natural diamonds. This variance stems from the fact that CVD diamonds are synthetically crafted in a laboratory setting, a process that usually concludes within a month. In contrast, natural diamonds take billions of years to develop, necessitating mining companies to invest vast resources in securing land, conducting excavations, establishing mines, and employing substantial workforces. While creating CVD diamonds demands substantial investment in specialized, often expensive equipment, along with a highly skilled workforce, the efficiency of the process ultimately renders it more cost-effective than traditional mining methods.

CVD diamond price vs natural diamond

AspectCVD DiamondsNatural Diamonds
Price RangeGenerally lower in costHigher in cost
Production TimeWeeks to a monthMillions of years
Formation ProcessLab-created under controlled conditionsFormed naturally in the earth’s crust
Mining and LaborRequires specialized equipment and laborExtensive mining efforts and labor-intensive
Environmental ImpactLower impact, less environmentally disruptiveEnvironmental concerns with mining
RarityProduced on demand, more readily availableLimited availability, inherently rarer

CVD Diamond Price vs Natural Diamond

Our recommendation leans toward selecting a lab-created HPHT diamond over a CVD diamond. HPHT diamonds consistently maintain higher quality without displaying the characteristic cloudiness often seen in post-growth treated CVD diamonds.

Choosing between natural and lab diamonds boils down to a personal preference. In simple terms, it’s a choice between an affordable, assuredly ethical, and ecologically sustainable option (CVD or HPHT diamonds) versus the marvel of nature formed over billions of years (natural diamonds).

Our consultants possess extensive training and profound knowledge of both lab-grown and natural diamonds. To assist you in making an informed decision, we can present a selection of the finest lab-grown and natural diamonds tailored to your preferences and budget. Reach out to our experts for further guidance.