How to identify diamond is CVD?

The Gemological Institute of America (GIA) tells that four Apollo rough crystals and 4 Apollo faceted crystals were tendered to GIA’s Gem Trade Lab (GTL) for testimony and research. the ECU Gemological Laboratory (EGL) and gemologist Antoinette Matlins even have inquired similar Apollo CVD diamonds.

cvd diamond machine

The labs say the identification of the new CVD material is fairly straightforward, but whether or not the typical retailer/gemologist can roll in the hay remains uncertain.

GIA GTL reports, “Characteristic stress patterns were recognized [under the microscope], which were separate from those seen in natural diamonds.” The lab also signs, “The CVD synthetic diamonds revealed strong red fluorescence while given to high-energy UV radiation within the De Beers DiamondView.” The DiamondView was designed to detect synthetic diamonds.

Observations by EGL USA include seeing clouds of white particles in one plane. EGL’s Branko Deljanin says these inclusions can show up in natural diamonds also but tend to be more dispersed. He also notes that retail jewelers studying CVD diamond under shortwave ultraviolet may even see yellow-green fluorescence that’s one or two degrees stronger than under long-wave UV.

Using specific spectroscopy instrumentation, GIA noted that CVD diamond has “a relatively solid photoluminescence emission at 737 nm thanks to track impurities of silicon.” Silicon isn’t found in natural diamonds.

cvd diamond lab test machine

Both laboratories state that jewelers who see inclusions or fluorescence almost like those described here should send the diamond to the knowledgeable lab for further study. like HPHT, Deljanin says, the classification of CVD diamond needs advanced instrumentation to conclusively identify the high-quality single- crystal CVD diamond.

Matlins takes a special view. “It’s a simple identification if you are doing the proper tests with proper techniques,” she says. She recommends the subsequent steps:

  1. Use a “dual” electronic diamond tester—one that tests for thermal conductivity and electrical conductivity—to approve the stone you’re examining may be a diamond.
  2. Check to ascertain if the diamond is Type II—the colorless synthetic diamonds produced by Apollo are all Type II. If it’s Type I, it isn’t synthetic. “As a pre-screener, use the SSEF (Swiss Gem Lab) Diamond-Type Spotter and reduce any doubt,” says Matlins. the sort Spotter shows whether the diamond is transparent to shortwave ultraviolet. If you hold the SWUV light over a kind II diamond, the SWUV will undergo the stone and cause the platform of the Spotter to fluoresce green. “If there’s no green reaction, you are doing not need to worry,” says Matlins. “It’s not an artificial colorless/near-colorless CVD diamond.”

If you see the green, then you’ve got a kind II diamond. Search for evidence that it’s a natural Type II diamond, a CVD synthetic, an HPHT-treated diamond, or a CVD diamond that also has been HPHT enhanced.

  1. Check fluorescence employing a modified technique. If the stone may be a Type II diamond, examine the stone with an ultraviolet source that gives long-wave and shortwave emission. Note the reaction under each wavelength. To use the ultraviolet source to work out whether the stone may be a natural or synthetic diamond, do the following:

View the diamond on a black background. If possible, place the stone during a table-down position.

Hold the lamp as on the brink of the diamond as possible.

Be sure the space is totally dark. The stone must be viewed in lightlessness to ascertain the reaction.

Note the result to long-wave; repeat using shortwave.

To determine if a stone may be a CVD synthetic, Matlins goes right to the UV unit. Quick test: If it fluoresces blue, it’s not synthetic. “Natural diamonds can fluoresce almost any color, but the foremost common fluorescent colors seen are blue, yellow, and white. However, blue fluorescence is an actual confirmation of natural diamond—only natural diamonds fluoresce blue.”

When natural colorless diamonds display fluorescence, the result is usually strongest under long-wave UV, becoming smaller when viewed under shortwave. Synthetic diamonds typically show the opposite reaction, showing the most powerful reaction under shortwave.

In the case of the new synthetic colorless/near-colorless CVD diamonds, the fluorescent reaction to the above technique is distinctive: a really dark brownish-red fluorescence under long-wave UV, becoming slightly stronger under shortwave, or red under long-wave, which changes to moderately strong yellowish/greenish under shortwave, is positive confirmation of synthetic diamond. In some cases, the reaction is going to be weak-to-moderate greenish/yellowish under long-wave, becoming much stronger under shortwave. This also indicates synthetic. a little number has exhibited phosphorescence under shortwave, which is a positive confirmation of synthetic.

If the diamond’s fluorescence shows the stone is synthetic, no further steps are needed. However, when seeing any Type II diamond, if there’s no fluorescence following either wavelength or if the fluorescence symbolizes natural diamond, submit the diamond to a grave laboratory to work out whether the color is natural or the results of HPHT treatment.

Matlins worries that the retail trade won’t take this seriously. “The trade has been so continuous that the colorless stones wouldn’t be hurting from this that jewelers are growing to continue utilizing their diamond testers and think that they’re covered.”

Apollo Diamond’s Robert Linares says the corporate is cooperating with the jewelry industry to make sure detection and full disclosure. “We will have full disclosure on rough material, and cut diamonds are going to be laser engraved and amid a certificate,” he promises.

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