Lab Certificate Myths & Facts


MYTH - A beautiful lab certificate guarantees a beautiful diamond.

FACT - We reject hundreds of diamonds that have “beautiful” certificates, but do not have that “beauty” when examined in person. The dimensions on the certificate may look ideal, but the diamond has minimal fire and scintillation. The clarity grade on the certificate may indicate a diamond with no visible inclusions, but we can see an inclusion as soon as we open the diamond paper. The symmetry on the certificate may read "excellent," but the diamond just doesn’t look right when placed on top of a mounting.



MYTH - An independent lab is always independent.

FACT - In October, 2005, the GIA fired 4 laboratory workers and the head of its New York lab amid allegations that it falsified diamond grading reports (click here to read an article on this subject). An unethical lab, or unethical lab employees, could give softer grades to diamond manufacturers or wholesalers who want to increase their profits. Even absent actual falsification, a lab may have "flexibility" when it comes to grading diamonds for its larger customers.

That's why it is always important, regardless of any lab report, to view a diamond yourself with a reputable jeweler who will take the time to show you the diamond in detail, using a microscope and color grader, and explain why the diamond is graded the way it is. You should be comfortable with and understand the grading.



MYTH - A diamond will receive consistent grades among laboratories.

FACT - A recent test by a jewelry organization selected 17 diamonds and sent each diamond to 3 labs - GIA, AGS and EGL. The diamonds were anonymously submitted from three different sources. None of the 17 diamonds were given the same grade for both color and clarity by all 3 labs.



MYTH - A diamond certificate is a scientific analysis of a diamond’s cut, color and clarity.

FACT - Diamond grading is subjective. A grading report is the grader's opinion, not a fact. We consistently find diamonds with lab certificates that, in our opinion, grade the diamond too high in one or more areas. We consider a lab certificate as just another one of the many tools we use when evaluating whether a diamond meets our strict standards.



MYTH - The beauty, fire and scintillation of a diamond’s cut can be determined by analyzing percentages, angles and millimeters.

FACT - While it is true that you can eliminate some diamonds if these factors are way out of line, you cannot determine the true beauty of a diamond’s cut without viewing it yourself. Each diamond has it’s own personality. You should never choose a diamond from its certificate “profile.” You need to see the diamond and personally evaluate it’s beauty to determine if it is right for you.



MYTH - One lab’s certificates are better than or stricter than another.

FACT - In the 17 diamond test, no one lab was consistently stricter than the others. While one lab graded a lower color on one diamond, it gave a higher clarity grade to another. No pattern of strictness or leniency was shown.



MYTH - I should never buy a diamond graded by "XYZ" lab.

FACT - We never eliminate a diamond based on its lab. The lab is not important to us because, whether it’s GIA, AGS, EGL, another lab or no lab, we grade the diamond ourselves. We are the ones selling the diamond, not the lab. It is our reputation attached to the diamond, not the lab’s reputation. The grade we put on any diamond is the grade we stand behind for that diamond, even if a lab gives it a higher grade.



MYTH - A one-grade change in color or clarity can’t make that much difference in price, so grading strictness is not that important.

FACT - Diamond prices are dramatically dependant on color, clarity and cut. A difference of only one color or clarity grade can result in price variations of up to 25%. In addition, diamonds that are improperly cut can sell at the wholesale level for 40 –70% less than a well-cut diamond of identical color and clarity. A strict grading jeweler will protect his or her customer against over-paying for an over-graded diamond.



MYTH - A diamond is a commodity. Two diamonds of the same size, color and clarity are really identical.

FACT - No two diamonds are alike. Each diamond is unique, and has its own pluses and minuses, it’s own personality. Some diamonds fall at the high end of a grade, and others fall at the lower end. We examine thousands of diamonds in order to select the few that stand out from the rest, the diamonds we are proud to recommend to our customers. We won’t recommend a diamond unless we’d wear it ourselves.



MYTH - It’s just a small spot that I can see. It’s not that noticeable, and I can live with it.

FACT - Many jewelers show diamonds that have one or more inclusions that can be seen with the naked eye. Why do they sell these diamonds? Because they cost significantly less, and the jeweler can make a greater profit. He will tell you that it’s so small it won’t bother you. Be wary of this thinking. Once you see a visible inclusion in your diamond, no matter how small, it will become all that you see. That inclusion will seem to get bigger and bigger each time you look at the diamond, and will prevent you from enjoying its true beauty.



MYTH - Grading standards at labs have strengthened in recent years.

FACT - From the many "certified" diamonds we see, it is a fact that grading standards have loosened significantly in past years. It used to be that if anything was eye-visible from the top of a diamond, it was given an I-1 or lower grade. SI-2 and above were reserved for diamonds that had nothing eye-visible from the top. Now even the world’s biggest labs have relaxed (click here to see two examples). This is another reason to never buy a diamond without seeing it first.


603 Wisconsin Ave N. Fond du Lac, WI 54937 920-922-6259
STORE HOURS: Mon thru Fri 9:00am - 6:00pm, Saturday 9:00am - 3:00pm


Copyright 2019 C. W. Smith Jewelers, Inc. All rights reserved.
Wisconsin Website Design by BrownBoots Interactive, Inc.