1.35Carat Excellent Polished Cushion Brilliant I SI1 EX EX HPHT Loose CVD Diamond

1.35Carat Excellent Polished Cushion Brilliant I SI1 EX EX HPHT Loose CVD Diamond

About Diamond Tester

 As HPHT method involves using metal catalyst, it is hard to avoid some metals entering the crystal during growing process, so HPHT diamonds might be magnetic. And if the magnetism is too strong, diamonds will not be able to pass the diamond teste. Because CVD diamonds are formed by mere gas, they can be produced without magnetic and are able to pass the diamond tester pen.

  In the 1990s, chemical vapor deposition (CVD) was used to synthesize diamond films, which were deposited on solid-phase substrates to form polycrystalline films of diamond for industrial use. 2003 saw the synthesis of gem-quality single crystals by Apollo in the USA, and commercial production began. More recently, the Geophysical Laboratory of the Carnegie Institution of Washington, USA achieved a CVD synthesis rate of 100μm/h to produce a 10ct, half-inch thick single-crystal diamond.