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What is a High Pressure High Temperature (HPHT) Diamond?

What is a High Pressure High Temperature (HPHT) Diamond?

A diamond is forever. That much is true. But are there enough diamonds for everyone? When the extraction of this precious stone from the earth becomes too slow and harmful to meet the demand, it is natural to look for alternatives. Ever since the discovery of diamonds, curious minds have searched for ways to recreate the precious stone on their own. The HPHT diamond is the product of one such experimental endeavor. 

Having earned a reputation for itself, the HPHT diamond is something you need to know about if you need to make a well-informed decision while purchasing diamonds. Diamondrensu is here to give you a brief rundown on everything related to HPHT diamonds.

hpht diamond3.01 CT Radiant Cut Lab Grown Diamond Engagement Ring


With the advancement in technology, there is no lack of synthesized diamonds today. However, we know this was not always the case. The crystallized pure carbon deposits found miles under the ground are tricky to replicate in a lab, but humankind has persevered to achieve this. The projects to grow diamonds in labs started in the 1940s, but the desired results came along much later. 

The first successful recreation of diamonds was done by a team put together by General Electric. The process was called HPHT or the High Pressure, High Temperature technique, where the environmental conditions that facilitate the formation of diamonds in natural settings were recreated. The technique may have been dangerous in its nascent stages due to the involvement of high levels of pressure and temperature. Still, scientists have perfected the technique to eliminate the hazards. 

The HPHT Process

All the controversies and rumors aside, the HPHT process is not as complicated as you think. Simply put, it is a carefully controlled technique that recreates the high pressure, and temperature found miles under the earth to form a diamond. The process starts when a small piece of natural diamond or seed diamond is placed in a chamber. This unit can be described as the HPHT diamond machine if you are inclined to. 

The chamber is filled with carbon and exposed to extreme pressure levels, approximately 1.5 million pounds per square inch, using equipment such as a belt press or cubic press. At the same time, the HPHT diamond machine maintains a temperature of 2,700°F in the chamber. This makes the carbon melt and accumulates around the seed diamond in layers. Once the layers crystallize and cool down, HPHT diamonds can be collected.

Another use of the HPHT process is applying it to premature diamonds to add color to them. Here, premature or diamonds that are not fully crystallized are collected from volcanic regions, and the labs finish what nature started. When a similar pressure and temperature of around 3,700°F is applied to gems that contain nitrogen, it turns yellow, whereas others that are free from nitrogen become colorless. 

This process completes the maturation of the diamond, and the HPHT maturation is a permanent process. Even though heat and pressure are applied to create these diamonds or complete their maturation, they still have similar composition and chemical properties to earth-mined ones. One important fact to keep in mind about this method of synthesizing diamonds is that only high-clarity diamonds can be used for HPHT. When diamonds with lower clarity are subjected to this process, they may get fractures and inclusions, become frosted, or even explode. Thus, careful examination of the diamond that goes into the chamber is critical to avoid the destruction of the stone.

The Durability of HPHT Diamonds

Diamonds are the hardest substance on earth, regardless of where they are formed. If you are in the diamond market, you can expect your HPHT diamond jewelry to be as beautiful and durable as the ones mined from the ground. You don’t need to worry about changes in the quality or color of the diamond over time, either. 

Being significantly budget-friendly compared to natural diamonds, you can go for more elaborate designs and bigger stones when purchasing HPHT diamonds. You can get everything from vintage halos to pave settings with cultured diamonds at the price of a simple natural diamond solitaire. Moreover, lab grown diamonds are free from impurities and minute inclusions compared to natural diamonds. This means that you can have a beautiful engagement ring like this or a stunning pendant like this to pass down as heirlooms. 

hpht diamond wedding band1.38 TW Emerald Cut HPHT Diamond Wedding Band

HPHT Diamonds: Looking Forward

The future of all synthesized diamonds looks bright, thanks to millennials and Gen-Z's awareness as shoppers. Both local jewelers and giant labels carry lab grown diamonds now to appeal to the younger crowd. So despite the older generations claiming HPHT diamonds to be fake, the majority of today's market knows better. 

Studies also show that the ethical nature, affordability, and increased eco-friendliness of the diamond process make them more attractive to shoppers today. In addition, for a crowd that has been used to personalized customer experience, synthetic diamonds make way for customizations that cannot be easily achieved with natural diamond jewelry. 

Some Lab Grown Diamonds You Might Like

hpht diamonds3.0 MM Round Brilliant Cut Lab Grown Diamond Eternity Wedding Band

This elegant three-sided pave set sparkling lab grown diamond eternity band is exactly what you need to make your special day extra special. Pairing well with any engagement ring, you can easily stack this one on top of your engagement jewelry without the fear of a fashion faux pas. Being simple yet exceptionally gorgeous, this ring complements any accessory you match it with. Own the accessory game on any occasion you show up with this lab grown sustainable diamond ring. 

oval lab grown diamond earrings
IGI Certified 2.02 TW Oval Lab Grown Diamond Earrings for Women

When it comes to accessorizing, there is a fine line between classy and over-the-top. This oval-cut pendant is one way to stay on the safer side of classy. This beauty comes with an 18-inch chain and is a perfect gift for birthdays and anniversaries. The gleaming oval stone is classically captured by the four-prong setting with an east-to-west setting. When combined with the chain in rose gold metal tone, there is no way anyone can take their eyes off this piece. With room for more personalization, this pendant can be the daily wear jewelry that you have been looking for. 

hpht diamond engagement ring1.03 CT Pear Blue Color Lab Grown Diamond Engagement Ring

Get engaged while following all the traditions because you have got something new and something blue taken care of. This 1.50-carat marquise-cut diamond is a stunning creation that can blow your partner’s and family’s minds away. The blue color is a touch of sophistication that every wedding needs, and there is no better way to include it than through the engagement ring. 

This stunning ring comes with a line of round brilliant lab grown diamonds set in a marquise halo surrounding the blue diamond at the center. Adding more beauty to the design, a tiny round cut diamond wraps three fourth part of the dome shank. The promise of lifelong love and commitment has never looked better. 

hpht lab grown diamonds
1.50 CT Heart-Shaped Lab Grown Diamond

Custom jewelry is a very special gift that you can give someone. From the careful selection of the design to mindful curation of the gems, a lot of thought goes into custom jewelry, and that makes receiving it all the sweeter. Be it a charm for a bracelet or a pendant, this heart-shaped colorless diamond is a gift that beats all others as the perfect Valentine’s day gift. Even for a special anniversary, you can show how close your partner is to your heart with a delicate style diamond set in a design of your choice. If you want to go big for an occasion, this is the right choice of diamond.  

round hpht diamondsMinimalist Round Lab Grown Diamond Wedding Band

Minimalism is all the rage now. If your partner favors this aesthetic, then that’s the only reason you need to invest in this minimalist beauty. An eternity band represents the eternal love that you share, and the diamonds add to this symbolism. This three-fourth diamond engagement ring can be worn alone or stacked with another ring. If functionality and minimum obstruction is something your partner seeks in accessories, this band is the most appropriate choice you can make for a wedding ring. 

pink lab grown diamond1.12 CT Heart Shape Pink Lab Grown Diamond for Engagement Ring

In Conclusion

To the naked eye, HPHT diamonds and earth diamonds look all the same. They are quite similar in quality too. There are only two notable differences between the two types of diamonds. One is extracted from the ground, while the other is produced in careful lab settings. Unlike natural diamonds, the gems created using HPHT are sustainable and conflict-free. 

If you are looking for a durable, sustainable, and affordable diamond, HPHT diamonds are a great choice. They are everything a natural diamond is, minus the dark stories entangling the industry. In addition, Diamondrensu has an exceptional range of lab grown diamond jewelry and diamond alternatives. Visit  to find the jewelry of your dreams.