HPHT vs. CVD: Which is Better for High-End Jewelry?

When it comes to lab-grown diamonds, jewelers are often presented with two choices: HPHT (High Pressure High Temperature) and CVD (Chemical Vapor Deposition). While both are real diamonds, they are not created equal, especially when it comes to high-end jewelry applications. At Kunlun Growth, we specialize exclusively in HPHT. Why? Because for colorless (D-E) stones, HPHT is structurally superior.

1. The "As-Grown" Color Advantage

One of the biggest secrets in the industry is that many CVD diamonds are grown with a brownish tint. To fix this, they undergo post-growth treatment (essentially an HPHT treatment!). However, quality HPHT diamonds are "as-grown". Our stones come out of the press with a natural D-E color structure. They do not require masking or treatment to look white. This "natural" whiteness tends to look crisper and brighter in engagement rings.

2. No Striation (Grain Lines)

CVD diamonds often suffer from internal graining or "striation" due to the layer-by-layer growth process. This can sometimes make the diamond look hazy or milky. HPHT diamonds grow in a way that mimics the Earth's natural crushing force. The result is a crystal structure that is incredibly dense and free from the layer lines found in CVD stones.

3. The Phosphorescence Issue

Some cheap HPHT diamonds have phosphorescence (glowing in the dark after light exposure). However, top-tier manufacturers like Kunlun Growth use advanced catalysts to eliminate this. When you buy gem-quality HPHT from us, you are getting inert, stable stones.

Conclusion: Why Choose HPHT?

If you are looking for large carat, high-color (D-F), and high-clarity (VVS) diamonds, HPHT offers the best value and quality consistency on the market today.