HPHT VS CVD
High temperature and high pressure method VS chemical vapor deposition method
High-Pressure High-Temperature (HPHT)：
HPHT is a process that simulates the temperature and pressure conditions of natural diamonds deep underground around 200 kilometres. The diamond seed is placed in a large mechanical press where high pressure and high temperature are applied. The machine can generate extremely high pressure and temperature, ranging from approximately 1300 to 1500 degrees Celsius and 40,000 to 60,000 atmospheres of pressure. The carbon lattice rearranges itself according to the diamond seed and gradually grows layer by layer until it reaches the desired carat weight.
Chemical Vapor Deposition (CVD)：
The basic principle of CVD is to place the diamond seed in an ion gas reactor in a vacuum and introduce a carbon-rich gas at low temperatures. Through the high-temperature decomposition of methane gas, plasma of carbon atoms is generated, allowing the carbon atoms to form a thin film on the diamond and deposit diamond layers.
