While both HPHT (High Pressure High Temperature) and CVD (Chemical Vapor Deposition) diamonds are made of pure carbon and share the same diamond crystal structure, their durability and hardness can vary based on several factors beyond the basic creation method. Let’s break it down:

1. Hardness of Diamonds:

• Hardness is determined by the crystal lattice structure of the diamond. Since HPHT and CVD diamonds are both diamonds, they share the same hardness rating of 10 on the Mohs scale, which is the hardest material on Earth.
• The atomic structure of both types of diamonds is the same as natural diamonds, meaning scratching resistanceis identical for both. Whether it’s an HPHT diamond, a CVD diamond, or a natural diamond, the outer layer is equally resistant to scratching.

2. Structural Integrity:

• HPHT diamonds are grown in high-pressure, high-temperature conditions that mimic the natural diamond-forming process deep within the Earth. While this method is tried-and-true for producing diamonds, it can sometimes result in slightly irregular crystal formations or internal flaws, such as inclusions.
• CVD diamonds, on the other hand, are created through a chemical process in a controlled environment, leading to more uniform growth. The process allows for better control over the number and placement of inclusions, which means CVD diamonds often have fewer defects. These diamonds tend to have a more consistent structure, which might make them slightly more durable in terms of resisting internal flaws.

3. External Durability (Impact Resistance):

• In terms of overall durability, both HPHT and CVD diamonds are similarly resilient to impacts, wear, and tear. The external physical properties, such as chipping or fracturing, are also comparable between the two, given that both are made of 100% diamond material.
• However, the internal quality (presence of inclusions, impurities, and structural integrity) can affect the durability of diamonds in specific scenarios, such as extreme impacts. A diamond with many inclusions might be more prone to breakage under intense pressure, but this would generally only affect diamonds with low-quality grading—whether HPHT, CVD, or natural diamonds.

4. Conclusion:

• HPHT diamonds may have minor inclusions or irregularities due to the extreme pressure and temperature, but they are just as durable and hard as natural diamonds.
• CVD diamonds often have fewer internal flaws and a more consistent structure, potentially making them slightly more resilient to breakage under normal conditions. However, both types of diamonds are equally hard and durable overall.