High Pressure High Temperature (HPHT)

GE developed the High Pressure High Temperature or HPHT process to enhance the tinted color of some diamonds especially when it is still in its rough state. Through this treatment, a significant improvement in the diamond’s clarity can be observed, thus improving its grade and its price value as well. Approximately 1% of all gem quality diamonds are suitable for this process.

High Pressure High Temperature chamber

When these diamonds placed inside the HPHT chamber or furnace are exposed to very high temperature and very high pressure, similar with the temperature and pressure under the Earth while the diamond is developing, the diamond’s molecular structure is altered producing a whiter color and the diamond changes from brownish tint to colorless or near-colorless. This process is also considered as permanent treatment and is almost always impossible to detect.

“Before and After” HPHT procedure. The diamond’s natural brown tint was removed
by permanently altering the molecular structure of the diamond

The Gemological Institute of America uses very expensive equipment to verify if a diamond has indeed gone through HPHT treatment. Once verified, a note is included on the diamond’s grading report for perusal or as reference.


For more information on this topic visit our Diamond Education & Resource Center

Princess Cut Diamond Engagement Rings Over 18,000 certified diamonds to choose from!

Fracture Filling

Diamonds undergoing natural processes deep beneath the surface of the Earth often capture or trap other elements during their development. One of the most common trapped elements is air. This trapped air makes a diamond unappealing even after it has been cut and polished because the air pockets may appear like tiny cracks inside the diamond. The trapped air is visible to the naked eye through the refraction of light in the diamond that looks different compared to when light passes through the air pocket.

In the mid 1970s, an Israeli scientist developed a treatment method to fill this pocket of air. Using a vacuum process, he inserted into the pocket of air through its natural surface opening a filler material designed to have almost the same exact refractive index or optical properties as the diamond. With the process, the light that entered was now refracted evenly throughout the diamond that improved its appearance as seen by the naked eye and sometimes even under magnification.

The presence of the filler material inside the diamond and even the process used do not alter the diamond’s carat weight, shape or color. Instead, the perceived clarity of the diamond is improved by one or two grades. The possible highest perceived clarity that can be attained via this process is a VS2.

The process of fracture filling is not considered permanent although normal wear and tear does not affect the filler which remains intact. But under certain circumstances, such as the diamond’s exposure to extreme heat from a jeweler’s torch as when fixing or cleaning jewelry, the filler material may evaporate or may sometimes darken its color and the diamond is back to its original “cracked” or imperfect look. There are guarantees though offered by most treatment labs for free reprocessing in case such an event happens.

A fracture filled diamond, or what is also popularly called as clarity-enhanced diamond, can be detected by most professional jewelers particularly because as light enters the filler material it creates a “flash” of light that can be seen under their magnification. This “flash effect” can generally be seen not face up but from the underside of the diamond.

The introduction of enhanced diamonds in the US happened in the late 1980’s where they were met with much controversy, especially since there were some unscrupulous diamond traders who were selling them without disclosing that these diamonds were in fact enhanced. There was a widely publicized case in Saint Louis, MO about a jeweler who committed suicide after receiving some negative publicity after he unknowingly bought a parcel of enhanced diamonds and sold them as non-enhanced.

Enhanced diamonds today are widely accepted by consumers and they play a major role in the diamond industry. When sold openly as enhanced diamond, the buyer is provided the benefit of a good bargain for such a precious stone. What is most important is that enhanced diamonds gives buyers the opportunity to get their dream diamond at an affordable price.


For more information on this topic visit our Diamond Education & Resource Center

Princess Cut Diamond Engagement Rings Over 18,000 certified diamonds to choose from!

Diamond Laser Drilling

Diamonds evolve from carbon so that at some point while making its way up to the Earth’s surface, its development may not be perfect causing some tiny black spots of undeveloped carbon to remain embedded inside the crystal. These are called carbon inclusions and these affect the grading of the diamond’s clarity after it has been cut and polished. The black carbon can be seen under magnification and sometimes even to the naked eye.

But this natural defect, however, can be corrected by means of laser drilling, a process developed in the early 1960’s by General Electric. The process is to drill into the diamond using a laser beam, a beam that has a diameter 100 times smaller than a strand of hair. Acid is then introduced into this minute hole towards the carbon inclusion by means of boiling the diamond in acid under high pressure. The acid bleaches the black carbon and turns it to white.

The black carbon is not actually removed but simply becomes invisible to the naked eye but the flaw is permanently corrected and even improves the diamond’s clarity. The laser drill method also does not affect the diamond’s carat weight.


Because laser drill treatments are permanent in nature compared to clarity enhancement of diamonds through other means, the Gemological Institute of America offers full grading reports of laser drilled diamonds. On the contrary, the GIA’s policy is not to offer grading reports on enhanced diamonds because they do not consider the process permanent.

It is not unusual though, that jewelers are more interested with clarity enhanced diamonds as opposed to laser drilled diamonds when in fact, laser drill treatment offers a permanent solution to carbon inclusions and improves the clarity of the diamonds. Probably because of the misconception that since laser drilling removes the inclusion, the diamond is not anymore in its natural and purest state. But the truth is, the laser drilling process allows the diamond to shine in its true brilliance as it was always meant to be.


For more information on this topic visit our Diamond Education & Resource Center

Princess Cut Diamond Engagement Rings Over 18,000 certified diamonds to choose from!

Diamond and Jewelry Certificates & Appraisals

Since the Gemological Institute of America (GIA) is one of the most respected gemological laboratories in the world, it is where diamond companies submit their diamonds for the necessary diamond grading reports.

The diamond grading report, aside from containing the analysis of the four C’s of diamonds such as cut, clarity, color, and carat weight, likewise reports on the diamond’s measurements, angles and proportions of its facets, imperfections, like inclusions and blemishes, and cutting workmanship. The report, however, does not contain an appraisal of the value of the diamond.

The need for these diamond certificates is important as it establishes the true quality and genuineness of the stone. In addition, the report gives an objective comparison through an unbiased and professional examination by a gemological laboratory like that of the GIA. The diamond certificate likewise facilitates smooth transactions by providing a dependable basis for the gem’s price and insurance.

Gem grading laboratories abound all over the world but not all of them have a highly known reputation like the GIA. Some gem labs have questionable ethics. The GIA, a non-profit organization that is not engaged in buying and selling diamonds, has been known as a leading authority on diamonds the world over. They have the highest standard of grading reports carefully drawn and showing the exact position, size and shape of every internal inclusion and external blemish a diamond possesses and it is very strict in assigning color and clarity grades.

Aside from diamond grading reports made by grading laboratories, there are also appraisal certificates issued by an independent appraiser or an appraiser connected with the jeweler who is skilled in the process of evaluating the genuineness and quality of diamonds. They are usually well experienced in the business of buying and selling diamonds, a graduate gemologist, particularly for diamonds, or jewelry professionals engaged in the trade of diamonds. Their opinions can be backed up by diamond certificates from gemological laboratories, if there are any. They then produce their independent evaluation that includes, unlike the GIA, information on the jewelry component and a full description of the article.

In addition, the appraisal certificates contain the estimated total retail replacement value for the complete item. Unlike a diamond gem lab, the appraiser determines the current market value of the gem after considering its quality and marketability which can differ from one appraiser to another. This valuation helps in determining whether or not its insurance coverage is adequate. In insuring jewelry, all insurers require a copy of the jewelry appraisal as, together with grading certificates, the appraisal certificates can shed light on the origin and genuineness of the jewelry as well as its insurability.


For more information on this topic visit our Diamond Education & Resource Center

Princess Cut Diamond Engagement Rings Over 18,000 certified diamonds to choose from!