• 3. Crystal morphology

HPHT diamond:

It usually grows into a truncated octahedron shape and has 14 different growth patterns.

CVD diamond:

It is mostly cubic in shape, or appears in the form of flakes or plates.

• 4. Product purity and impurities

HPHT diamond:

During the growth process, metal catalysts are required to be introduced. As a result, the residue of metal particle impurities is inevitable. HPHT diamonds have relatively more internal impurities and may contain impurities such as nitrogen and boron. Some of them are magnetic due to these impurities.

CVD diamond:

Metal catalysts are not used during the growth process, CVD diamonds usually have higher purity, are free of metal impurities, rarely contain impurities like nitrogen and boron, and generally do not exhibit magnetism.