HPHT vs CVD Lab Grown Diamonds: Which is Best for You

Lab-grown diamonds have turned over the way people purchase engagement rings and fine jewelry. You're probably asking yourself which one will suit your needs better. These gems are produced by two main technologies: HPHT and CVD. They both give us genuine diamonds that are visually and physically indistinguishable from natural ones.

We've prepared this guide to shed light on the differences between HPHT- and CVD-lab-grown diamonds. You will understand the working mechanisms of each method, how they differ, and which one is best for your budget and taste. Thus, in the end, you'll be able to tell which diamond-making process aligns more with your values.

What Is HPHT Diamond Technology?

HPHT is an abbreviation for High Pressure High Temperature. This method is basically Earth in a lab where natural diamonds are made under intense pressure and heat. Inside the press, scientists take a tiny seed diamond crystal and spread carbon around it. The machine exerts the tremendous force. Besides, the temperature can be as high as in a scorching furnace. Carbon dissolves and subsequently crystallizes on the seed under such conditions.

Depending on the size, this factory-to-earth equivalent diamond takes anywhere from a few days to a few weeks. What you get is a real diamond growing incrementally. As we know, General Electric is credited with inventing this technology in the 1950s. The method has since been used to produce diamonds for industrial and jewellery applications.

HPHT lab diamonds begin in a cubic press or a belt press. In a cubic press, six anvils work together to deliver uniform, enormous pressure.

What Is CVD Diamond Technology?

The full form of CVD is Chemical Vapor Deposition. HPHT is a physical growth process, while CVD is a chemical one. At the start of the procedure, that thin diamond piece is positioned in a hermetically sealed deposition chamber. The chamber is filled with a preparation of carbon-containing gases such as methane and hydrogen.

Even though the chamber temperature increases, it is not as high as in the HPHT methods. The gas molecules are divided using microwaves or another energy source. Carbon atoms then layer after layer on the diamond seed.

This technique is like the slow coming of snowflakes on a window. The quality fabrication of CVD lab diamond requires only a few weeks; with time, scientists will be able to manipulate the process more efficiently, yielding the anticipated output. One can stop the progression, take stock, and even make tweaks to the setup when necessary.

The commercial introduction of CVD technology was in the 1980s. Advancements over the last 20 years have turned it into a method for producing high-quality lab-grown diamonds. The preference nowadays of many manufacturers for large-sized stones is the CVD ‍‌method.

HPHT and CVD Lab Grown Diamonds

▶Quality and Appearance

Both techniques produce genuine diamonds with the same chemical composition as naturally mined diamonds. They both score 10 on the Mohs hardness scale. It is impossible to tell the two types of diamonds apart just by looking at them.

HPHT lab grown diamonds may contain remnants of the metal used as the growth medium in their inclusions. Such minuscule metallic traces are at a level that does not affect the overall look and, therefore, cannot be seen with the naked eye; however, sophisticated instruments may detect them. HPHT lab diamonds may display a very faint yellow or brown coloration, which must be bleached to reach colorless grades.

CVD lab grown diamonds usually have fewer metallic inclusions since they are grown in a cleaner environment. They are generally cleaner and thus require less post-growth treatment. Brown hues may appear in CVD lab diamonds due to their growth process. A great deal of CVD diamonds are heat-treated to remove these colors.

The colour range for both varieties is from D to Z, as with natural diamonds. The clarity scale is the same, with grades ranging from Flawless to Included. It is possible to achieve high colour and clarity grades for the highest-quality diamonds, regardless of their method of creation.

▶Cost and Value

CVD diamonds typically cost slightly less than HPHT diamonds of equivalent quality. The price difference reflects how efficient the production is, more than any discrepancy in quality. The CVD method is easier to scale, so the overall process is more streamlined.

Each of the two types is much cheaper compared to natural diamonds of the same specs. The biggest financial point of lab-grown diamonds is the savings. You gain the same kind of beauty and durability, but it comes at a fraction of the price.

▶Size and Production Capabilities

HPHT technology is more suited for making smaller diamonds. Most HPHT generators can efficiently deliver output of under two carats. To produce larger HPHT lab grown diamonds, more time and resources are required. The yield is inversely proportional to the size when the latter increases.

CVD stands out when it comes to the production of large-sized stones. There has been a growing number of multi-carat CVD lab diamonds in the market nowadays. Some labs have now been able to manufacture CVD lab grown diamonds of over five carats in size.

The rate of production varies with different methods. HPHT is capable of making diamonds quickly, but this is only restricted to small sizes. When it comes to the same size, CVD will take more time.

▶Environmental Impact

Both methods depend on electrical power to some extent. There are some very intense and short bursts of energy that HPHT consumes in order to reach the conditions of high pressure and temperature. CVD is carried out over a longer period of time but at a lower power level. The total energy usage per carat will eventually be very close to each other.

The carbon footprint depends on the type of energy that is used. If a lab decides to go for renewable energy, then the resulting diamonds will have almost no negative effect on the environment. On the other hand, if the facility is using the traditional way of getting energy, then the carbon footprint will be large.

Water consumption is kept down to a minimum for both processes. Neither of the two methods uses the huge quantities of water that diamond mining needs. In addition to that, the amount of chemical waste is also kept at a minimum compared to traditional mining operations.

The extraction of natural diamonds has a great impact on the Earth. Lab-grown diamonds do not cause such a land disturbance at all.

How to Identify HPHT vs CVD Lab Diamonds

By visual inspection, it is impossible to distinguish HPHT from CVD diamonds. Even professional jewelers usually require instrument support to ascertain the production method. The variations are real at the level of the atom and beyond the naked eye.

Gemological laboratories apply different procedures to identify the origin of the diamonds, including:

• Checking ultraviolet light-induced fluorescence patterns
• Using a high-power microscope to reveal characteristic growth patterns
• Measuring the amount of light that passes through various crystal facets
• Using a spectrometer to study the diamond's atomic structure

Some distributors will not tell you the method of the diamond's production. If it is important to you that your diamond is CVD or HPHT, then you should inquire beforehand. A trusted diamond store stands for its products' quality and honesty and provides its customers with full information on their diamonds' origins and production ‍‌processes.

Pros and Cons of HPHT and CVD Diamonds

Which Diamond Growing Method Is Right for You?

At the end of the day, whether you buy HPHT or CVD will be influenced by what matters to you the most. In general, the two ways used to produce diamonds do not create diamonds that are better than the other. You just need to determine what is more important to you at the moment.

If you like the idea of a small diamond below one carat, then get an HPHT lab diamond. Those stones are of very good quality and price. Their quicker production means that they will always be readily available in standard sizes. And in case you want a fancy colored diamond such as a yellow or blue, your best bet will be HPHT which will produce those naturally.

CVD is your weapon of choice, if you are looking for a bigger diamond over two carats. The CVD method results in larger diamonds with more uniformity. Besides, if you want the highest clarity grade possible, then CVD is a perfect way to go.

In fact, for a majority of customers, the factor of how a diamond is grown is less significant than the four Cs: cut, color, clarity, and carat weight. Initially, give priority to these features. With adequate cuts, both CVD and HPHT diamonds would be indistinguishable when set in a ring.

Your budget will also be heavily determining your choice. Always compare specific diamonds rather than making generalizations on the technologies. Since each diamond is unique, its price also has to be different based on its ‍‌qualities.

HPHT vs CVD: Final Verdict

Both HPHT and CVD produce authentic diamonds perfect for engagement rings and jewelry. They share the same physical properties, brilliance, and durability. The choice between them rarely makes a practical difference in your daily experience.

Conclusion

When comparing HPHT and CVD lab grown diamonds, these two technologies are just different ways of achieving the same result. The diamonds they produce are real and have identical chemical compositions to those found in nature. The quality of the diamond is not dependent on the method of production.

Instead of deciding based on the method, you should look at the specific diamond's characteristics. In other words, go for a superb cut, attractive color, high clarity, and the desired carat weight that fits your budget. Whether HPHT or CVD, either technology can supply you with the perfect diamond.

Are you looking for a diamond that is the perfect fit for you? Stop by Messi Jewelry and view our incredible selection of certified lab-grown diamonds. The entire collection is available with a professional, thorough grading report for each diamond, and both HPHT and CVD stones are held to the same high standards of quality and care. Our professionals guide you through selecting a diamond that complements your personality and budget.