Moyer Diamond Guide

Before we get to the 4C's, we want to tell you about the Moyer Diamond Difference. Our standards make just as much of an impact to the overall beauty of your diamond as the 4C's.

Approximately 99% of our natural loose diamonds are authenticated and graded by the world's foremost authority for diamond grading, the Gemological Institute of America (GIA). Because of this third-party certificate, our customers can rest assured knowing that there’s complete transparency with each and every diamond they see and/or purchase at Moyer.

Beyond the certificate, our customers can feel confident shopping at Moyer as every loose diamond at Moyer has passed through the hands of our one diamond buyer, a GIA Graduate Gemologist. Because all of our diamonds are purchased by one person, she’s able to apply the same level of scrutiny to each diamond, assuring each diamond meets our high quality standards. When it comes to selecting loose diamonds for our inventory, we are—to put it candidly—extremely picky. To learn about all of our loose diamond standards, please visit us in-person at our store or reach out to schedule a virtual diamond presentation.


The Four C's

The 4Cs of Diamond Quality is the universal method for assessing the quality of any diamond. As mentioned above, we trust the Gemological Institute of America (GIA) for the most accurate representation of diamond grading.  

Diamond Color

Diamond color actually means a lack of color. A chemically pure and structurally perfect diamond has no hue, like a drop of pure water, and consequently, a higher value. GIA's D-to-Z diamond color-grading system measures the degree of colorlessness by comparing a stone under controlled lighting and precise viewing conditions to masterstones or stones of established color value.

GIA's diamond D-to-Z color-grading scale is the industry's most widely accepted grading system. The scale begins with the letter D, representing colorless, and continues, with increasing presence of color, to the letter Z. Many of these color distinctions are so subtle that they are invisible to the untrained eye; however, these distinctions make a very big difference in diamond quality and price.

Fun fact: Color is the only factor that is not determined by examining the table or a top down perspective. Diamonds are actually graded for color by placing them upside down (with the table resting on the surface) on a pure white piece of paper.

Diamond Clarity

Diamond clarity refers to the absence of inclusions and blemishes. Natural diamonds are the result of carbon exposed to tremendous heat and pressure deep in the earth. This process can result in a variety of internal characteristics called "inclusions" and external characteristics called "blemishes."

The GIA Diamond Clarity Scale has 6 categories, some of which are divided, for a total of 11 specific grades.

  • Flawless (FL)
    No inclusions and no blemishes visible under 10x magnification
  • Internally Flawless (IF)
    No inclusions visible under 10x magnification
  • Very, Very Slightly Included (VVS1 and VVS2)
    Inclusions so slight they are difficult for a skilled grader to see under 10x magnification
  • Very Slightly Included (VS1 and VS2)
    Inclusions are observed with effort under 10x magnification, but can be characterized as minor
  • Slightly Included (SI1 and SI2)
    Inclusions are noticeable under 10x magnification
  • Included (I1, I2, and I3)
    Inclusions are obvious under 10x magnification which may affect transparency and brilliance

Diamond Cut

A Diamond's Cut Unleashes Its Light. Diamonds are renowned for their ability to transmit light and sparkle so intensely. We often think of a diamond's cut as shape (round, emerald, pear), but a diamond's cut grade is really about how well a diamond's facets interact with light.

Precise artistry and workmanship are required to fashion a stone so its proportions, symmetry, and polish deliver the magnificent return of light only possible in a diamond.

A diamond's cut is crucial to the stone's final beauty and value. And of all the diamond 4Cs, it is the most complex and technically difficult to analyze.

To determine the cut grade of the standard round brilliant diamond—the shape that dominates the majority of diamond jewelry—GIA calculates the proportions of those facets that influence the diamond's face-up appearance. These proportions allow GIA to evaluate how successfully a diamond interacts with light to create desirable visual effects such as:

Brightness: Internal and external white light reflected from a diamond

Fire: The scattering of white light into all the colors of the rainbow

Scintillation: The amount of sparkle a diamond produces, and the pattern of light and dark areas caused by reflections within the diamond

GIA's diamond cut grade also takes into account the design and craftsmanship of the diamond, including its weight relative to its diameter, its girdle thickness (which affects its durability), the symmetry of its facet arrangement, and the quality of polish on those facets.

The GIA Diamond Cut Scale for standard round brilliant diamonds in the D-to-Z diamond color range contains 5 grades ranging from Excellent to Poor.

Diamond Carat Weight

Diamond carat weight is the measurement of how much a diamond weighs. A metric "carat" is defined as 200 milligrams.

Each carat can be subdivided into 100 "points." This allows very precise measurements to the hundredth decimal place. A jeweler may describe the weight of a diamond below one carat by its "points" alone. For instance, the jeweler may refer to a diamond that weighs 0.25 carats as a "twenty-five pointer." Diamond weights greater than one carat are expressed in carats and decimals. A 1.08 carat stone would be described as "one point" or eight carats.

Only Natural Diamonds

We believe in providing our clients with jewelry and diamonds that hold value and can be considered an asset. For that reason, we are proud to offer our clients natural diamonds. We do not- and will not- sell lab grown diamonds. Here are a few reasons why we believe in only selling natural diamonds...


The value of natural diamonds comes from their uniqueness and rarity as a naturally occuring gem. According to Only Natural Diamonds, "The amount of natural diamonds 1 carat and larger recovered in a year would only fill one exercise ball." This rarity and finiteness make natural diamonds valuable. On average, natural diamonds retain inherent value appreciating in price by approximately 3% on average each year. On the other hand, lab grown diamonds can be replicated at unlimited quantities for pennies on the dollar to the wholesaling company.

upgrading, trading or selling

Because natural diamonds are rare and have intrinsic value, we will always allow our natural diamonds to be traded in (for a larger or better quality natural diamond) or sold back to us. We are a trustworthy source for both situations, offering our clients top-dollar for their natural diamonds. On the other hand, since lab grown diamonds do not hold value (especially since they're flooding the market with supply), it would be nearly impossible to sell your lab grown diamond at a fraction of the price you paid.

unique symbol of love

For centuries, diamonds have been a symbol of love. You gift the person you've fallen in love with a rare and unique natural diamond engagement ring. Like an individual's fingerprint, no two natural diamonds are identical.

When you're looking for a diamond for someone special, you want to make sure that you're getting the best. Rest assured that at Moyer, we are looking out for your best interest. We look forward to guiding you through the diamond process.