Types of Lab Diamonds
A brief history
Synthetic diamonds have been produced for industrial purposes since the 1950s and used in telecommunications, laser optics, as abrasives, and more. It wasn't until the 1970s that General Electric researchers created the first gem quality synthetic diamond.
By the mid 1980s, many manufacturers began growing commercial quality grade crystals. These were small in size and ranged from yellowish to brownish in color. To this day, quality of synthetic diamonds are continuously being improved-to the point where you cannot tell the difference with the naked eye.
So how are lab diamonds made you ask? There are two main major processes to create:
HPHT (High Pressure High Temperature)
Synthetic diamonds are produced in labs through equipment that mimics the conditions for a natural diamond from the earth: lots and lots of heat and pressure.
The result: flat bases and octahedral and cube facets.
The color of HPHT has evolved over the years as technology advances.
Lab made submitted to GIA labs have gone from orange-yellow, yellow, and yellow-orange, to color-less, near-colorless, and blue.
HPHT and other post growth treatments of diamonds can alter the gems color to pink, blue, and other colors.
Chemical Vapor Deposition (CVD)
This technique is newer. It involves breaking down carbon containing gasses inside a vacuum chamber and having carbon molecules crystallize onto diamond seed plates.
The result: Crystals are tabular in shape and are sometimes edged with graphite. This process often results in brown or yellow in color gems, but can become nearly colorless through HPHT treatment (as mentioned above). HPHT can also change the color of the gem to pink-to red in color.
Colorless CVD diamonds chosen to be polished as gems seem to have higher clarity than their natural counterparts.
