Replicating what’s happening deep underground is difficult, time-consuming and expensive, but the end result is the same as what’s been mined for centuries. There are easier ways to do this, but only the process we use, replicating nature to rearrange atoms to grow beautiful diamonds as unique as fingerprints. We do this because we care about the planet and want the jewelry and diamonds we sell to bring that same sense of care and growth into the personal relationships they symbolize.
The high-pressure, high-temperature method replicates the natural process of diamond formation under the Earth’s crust, acting like a giant pressure cooker.
It starts with the following: We stack diamond seeds, graphite and metal (growth catalyst) inside a small cubic cell, which is then placed in a hydraulic press. Under enormous pressure (5-6 GPa) and searing temperatures (~1500 °C), the graphite and metal begin to melt, eventually forming diamonds around the seeds. The whole process takes about 2-3 weeks from start to finish.
Grow in 14 different directions. Size is limited by cubic cell size and application technique (usually from 1 carat to 15 carat polished). The method of planting also affects the type of inclusions and possible color of the gemstone. For example, HPHT gemstones may contain metals due to applied technology. CVD stones can often have dislocations, resulting in a gray or milky white color.
Possible colors range from D to I, usually the colorless or near-colorless group.
Possible clarity from IF to I1, usually the VS clarity group.
All shapes are available, but pear/oval/marquise are rare due to low yields.
Chemical vapor deposition can be described as the growth of diamonds from carbon-containing gases. (Reactor picture)
The CVD process starts with the following: We place a diamond plate in a vacuum chamber and heat the plate to 800 ⁰C. The chamber is then filled with a carbon-rich gas (usually methane) that can also be microbeamed to 3000 ⁰C. This is done to break molecular bonds and release carbon atoms, which are then deposited on a diamond plate. The diamond grows slowly but firmly upwards (its length and width are limited by the size of the plate). CVD takes 1-4 weeks from start to finish (depending on desired weight).
Features: Unidirectional growth – upward, so limited by initial diamond plate size and application technology, usually no more than 5ct polishing. CVD gemstones are Type IIa unless they are colored.
CVD stones are usually nearly colorless, but are rarely better or lower. They may also have grey or brown tints.
In terms of clarity, CVD stones fall between IF and SI, mainly VS.
All shapes are available, but pears/ovals/marquises are rare due to low yields.