High Pressure, High Temperature (HPHT) method
Under 1500 degrees and 70 bars pressure, a small diamond seed is grown to a bigger rough diamond after few weeks.
Rough Diamond Size (HPHT) :
Carats | Grade | Color | Clarity | Polished Diamond Weight |
＜3CTS | 1st A-2nd B | D-F | VVS-SI | 0.003-1.0CT |
3-5CTS | 1st A-2nd B | D-F | VVS-SI | 1.0-2.0CT |
5-10CTS | 1st A-2nd B | D-F | VVS-SI | 2.0-4.0CT |
REMARKS | ||||
1st A | No impurities in the center, trace impurities on the surface | |||
1st B | No impurities in the center, trace impurities on the surface, less output than 1st A | |||
2nd A | Impurities in the center | |||
Chemical Vapor Deposition (CVD) method
A diamond plate is placed in 2 carbon containing gasses atmosphere: hydrogen and methane. The diamond plate will grow layer by layer when the plasma cloud detaches the carbon elements.
Rough Diamond Size (CVD):
Size | Grade | Color | Clarity | Polished Diamond Weight |
7*7mm | A | D-F | VVS-VS1 | 1.0-1.5CT |
9*9mm | A | D-F | VVS-VS1 | 2.0-2.5CT |
9.5*9.5mm | A | D-F | VVS-VS1 | 3.0CT |
12*12mm | A | D-F | VVS-VS1 | 5.0CT |
15*15mm | A | D-F | VVS-VS1 | 10CT |
High Pressure, High Temperature (HPHT) method
Under 1500 degrees and 70 bars pressure, a small diamond seed is grown to a bigger rough diamond after few weeks.
Rough Diamond Size (HPHT) :
Carats | Grade | Color | Clarity | Polished Diamond Weight |
＜3CTS | 1st A-2nd B | D-F | VVS-SI | 0.003-1.0CT |
3-5CTS | 1st A-2nd B | D-F | VVS-SI | 1.0-2.0CT |
5-10CTS | 1st A-2nd B | D-F | VVS-SI | 2.0-4.0CT |
REMARKS | ||||
1st A | No impurities in the center, trace impurities on the surface | |||
1st B | No impurities in the center, trace impurities on the surface, less output than 1st A | |||
2nd A | Impurities in the center | |||
Chemical Vapor Deposition (CVD) method
A diamond plate is placed in 2 carbon containing gasses atmosphere: hydrogen and methane. The diamond plate will grow layer by layer when the plasma cloud detaches the carbon elements.
Rough Diamond Size (CVD):
Size | Grade | Color | Clarity | Polished Diamond Weight |
7*7mm | A | D-F | VVS-VS1 | 1.0-1.5CT |
9*9mm | A | D-F | VVS-VS1 | 2.0-2.5CT |
9.5*9.5mm | A | D-F | VVS-VS1 | 3.0CT |
12*12mm | A | D-F | VVS-VS1 | 5.0CT |
15*15mm | A | D-F | VVS-VS1 | 10CT |
