Our Colored Stone Grading Guarantee
The purpose of our grading reports is to provide our clients with accurate information normally found in a gem lab report, plus a realistic grading of the quality of the gem. We have made every attempt to correlate our grading with normal gem trading practice, and to grade fairly and with discipline. We stand by our grades and put it in writing, but please note that our grades are our opinions.
Since gem grading is an applied skill, normal differences of opinion between qualified observers are to be expected. All grading is subjective and relative to the graders' training, experience, natural ability and ethics. The natural distribution of gems follows a bell curve, while grading systems are based on categories - like steps in a ladder. Normally, gems that are in the middle of a category will be easier to grade consistently, while gems that lie near the border between one category and the next will often be graded differently by different graders. Differences of one grade in each of the major categories of color, clarity, and cut are to be expected — those are just the limits of gem grading.
Significant differences between graders, for example where one person grades "extra fine" and another grades "good," indicate a problem. Such situations may require reexamination or in some cases, a third party opinion. Mardon reserves the right to designate a third party in case of reexamination, and will only use such institutions as GIA, AGTA, GRS, or similarly notable and reputable labs.
Wherever possible, we will state country of origin. If we don’t know for certain where a gem comes from, our report will state "Unknown."
In all cases, we disclose any type of gem enhancement and guarantee that disclosure to be accurate or your money back. Higher priced gems may be purchased subject to a lab report — please call to discuss. Lower priced gems may be submitted by the client to any of the following gem labs: GIA, AGTA, IGI, SSEF, GRS, or any lab of similar qualification or standing. If the report disagrees with our enhancement statement, we will pay the cost of obtaining the certificate, adjust the price, or refund 100% of the purchase price at the client's option.