Moissanite quality

What is “4C”?

Although it may not be widely known, moissanite has a similar shape to diamond, and unofficially, it has a variety of color, clarity, carat, and cut (polishing). It may be evaluated using a grade called 4C .

[Carat - Weight]
A carat is a unit of weight, not size. 1 carat = 0.2g, the heavier the weight, the higher the price.

Clarity is a standard that expresses transparency, and is evaluated based on the size, location, and nature of scratches, chips, and inclusions. From VVS1, the highest, to VVS2, VS1, VS2, SI1, SI2, I1-3, the higher the transparency, the higher the rating.

The first letter "D" in a diamond is considered to be completely colorless and transparent, which is the highest rating, and from there, in alphabetical order E, F, G, etc., the diamond becomes yellowish and the rating decreases accordingly. In the case of moissanite, colored raw materials are cheaper than colorless and transparent raw materials, so loose stones with a slightly colored color are relatively cheaper than colorless and transparent ones.

[Cut - Proportion]
As the name suggests, it is a standard that determines the beauty of the shine caused by the cut. While the other three elements are based on the gem's original properties, this evaluation is based on elements added by human hands. The highest grade is Excellent (optically ideal), and the evaluation is on a five-point scale: Very Good, Good, Fear, and Poor. The quality of moissanite also varies depending on the cutting technology of the production factory, so these are often reflected in the evaluation.

There are no clear international common standards for quality evaluation of moissanite.

The diamond has been evaluated based on the international quality evaluation standards established by GIA (Gemological Institute of America), and an internationally recognized certificate of authenticity (format varies depending on each appraisal organization) is issued. There are currently no clear evaluation criteria for moissanite.

There are some appraisal reports in circulation by GRA, an organization that claims to be a moissanite expert appraisal organization, but as has been mentioned and sometimes verified in various places, their authenticity and reliability are extremely poor, and caution is required. This is a general opinion.

Moissanite carat number calculation is special

As mentioned above, a carat is a unit of weight.
The total weight of the stones used is often reflected in the price of jewelry, and it is common for the weight of the stones actually used to be engraved on the jewelry as a stone grain stamp. When selling moissanite jewelry, there are many companies that engrave the stone grain of the moissanite used in the jewelry using the diamond equivalent when replacing it with a diamond. In other words, moissanite jewelry is often engraved with a carat based on diamond standards, but in accordance with the rules of the Jewelry Association, our store accurately measures the weight of the moissanite we use using a precision scale and stamps that number. doing.

Diamond, which is made only of carbon, and moissanite, which is a 1:1 compound of carbon and silicon, have different specific gravity. Therefore, when comparing the same number of carats, moissanite is about 10-15% lighter than diamond. Masu. In other words, When stamping a moissanite grain, if it is stamped as the equivalent of a diamond of the same size, depending on the size of the stone, there may be a large difference in mass from the actual moissanite. (Example: 4.25 ct moissanite ring = If the same size diamond equivalent is engraved, it will be 5 ct, with an actual weight error of 0.75 ct.) We consider this to be tantamount to deceiving consumers. Even if a customer asks us to engrave a diamond equivalent, we will strictly refuse to do so.

Below is
Some of the regulations established by the Japan Jewelry Association, a general incorporated association, are quoted.

Display regulations for materials, etc. of jewelry and precious metal products (cited from JJA)

(1) Units and numerical values ​​for the mass of gemstones When displaying the mass of gemstones, display the value in carats to the second or third decimal place. In that case, the ct symbol can be omitted.

(2) Gemstone measuring instruments and measurement methods The mass of gemstones must be determined by actual measurements using accurate measuring instruments.

(3) Displayed mass value of jewelry The displayed mass value of jewelry must not exceed the actual measured value. When replacing measured values ​​by rounding them, use the truncation method.

Moissanite color and clarity

Moissanite is not completely colorless and transparent, and there are cases where it has a slightly grayish tint under certain lighting conditions. In addition, there are some individuals that can be observed with a yellowish tinge similar to diamonds. However, with regard to this color, there have been remarkable advances in manufacturing technology in recent years, and it is possible to produce diamonds that are equivalent to D (highest rank, almost colorless and transparent) in the GIA diamond evaluation standards, or conversely, to produce diamonds with a slight tint. It has also become possible to create new things.

Next, regarding clarity, this also depends on the technology on the production side. Normally, at our store, we only select and use items that have no inclusions when visually inspected using a magnifying glass.
However, please be aware that some producers may sell loose or less transparent moissanite with inclusions as being of high quality.

Quality standards are up to the seller

Up to this point, we have briefly introduced the quality of moissanite and its evaluation standards. There is no such thing as a certificate of authenticity that provides a solid guarantee.

Unfortunately, it cannot be denied that there are dishonest sellers who take advantage of these aspects of moissanite and sell products with false ratings that clearly deviate from the actual quality. In some cases, the gemstone moissanite itself may be unfairly valued.

Compared to diamonds, especially natural diamonds, moissanite is a gemstone that can be obtained at a fairly low price, which is one of its major attractions, but for example, as I mentioned earlier, it has a “D” color standard as determined by GIA. Although the quality of loose moissanite is comparable to that of Moissanite, it is relatively expensive when compared to moissanite of other qualities, although technological advances have made it possible to produce beautiful pieces.

We sincerely hope that you will be able to pick up a piece of jewelry that will become a wonderful everyday companion for you.

*Please note that this translation is provided for informational purposes, and for any legal purposes or concerns, the original text in Japanese should be consulted.