What is a loupe and why do gemologists use it on diamonds and engagement rings?
What is a Jewelers Loupe?
A loupe is a handheld or machine device used in the diamond industry by trained diamond professionals to magnify a loose diamond, diamonds in engagement rings, or any piece of diamond jewelry you would like to inspect. Despite there’s being higher magnifications out there, the jewelry industry standard is 10x magnification, and in the hands of a trained professional, a loupe can be used very effectively in determining the quality of a diamond, by using it to inspect it’s clarity characteristics.
Why 10x Magnification?
If you look close enough you’re bound to find some imperfections in even diamonds rated FL or IF. Nothing is absolutely flawless if you look hard enough, that’s why GIA decided that there needs to be a set standard in which to grade diamonds effectively. The decided that 10x magnification to a diamond is actually ridiculously close, and serves as a great “rock” to build on. It’s at this 10x magnification that everything gets graded. However it’s also graded by 20×20 eyes, as well. Commonly known as “Naked Eye”. I’ll explain.
What is meant by "Clear to the Naked Eye"?
When someone says this, or that diamond is clear to the naked eye, what they are saying, is that you can not see any imperfections or inclusions without the aid of a jewelers loupe. In most case anything that is SI1 clarity and higher (and rated by GIA, AGS, or EGL USA) will be absolutely clear to the naked eye. That’s why properly graded SI1 clarities are the best bang for your buck. No one is going to take a diamond loupe to your diamond, they will visually inspect it, and see how clear it is.
If a diamond is clear to the naked eye, then it’s already a SI1 or higher clarity. The jewelers loupe magnified to 10x will determine the rest. How easy an inclusion is to see under 10x magnification will determine it’s final clarity grade. On the other hand if you can see inclusions with the naked eye, usually black inclusions, feathers, and cracks, then it will be an SI2 or lower. SI2 diamonds will show inclusions without the aid of a loupe, however you might have to look a little. I1 clarity you won’t have to look very hard. I2 clarities are very easy to see, and I3 clarities are typically used for custom jewelry, as the imperfections are glaringly obvious and unsightly. However the loupe is still used to with clarities SI2 and below because you need to be able to see everything and document it on a diamond certificate. The same with SI1 clarities and higher. Since you can’t see anything with the naked eye you will have to use a loupe, and depending on how easy it is to see the inclusions with a loupe, that will determine is final clarity and the diamond certifier would mark everything down on the diamond certificate.
Are loupes the only means of determining the clarity of a diamond?
There’s a little more to it than that. Loupes in whatever fashion they come in, such as a hand hold loupes, eye piece loupes, head band loupes, or even a machine operated loupe, are the first means in determining a diamond’s clarity. But then comes the Internally Flawless diamond, and the Flawless diamond. Both of these diamonds are considered flawless, meaning you can’t see any inclusions with a jewelers loupe. So they have to go one step further and that’s diamond polish. Usually diamond polish is the final determination between a FL and IF diamond. You can read more about it at “Diamond Polish and it’s effect on Diamond Clarity“.
What else are jewelers loupes used for?
Jewelers also use the loupe to perform an initial inspection of a piece of jewelry like engagement rings, right hand rings, earrings etc.. They use the magnification to see if there’s any damage, such as the prongs being scratched or dinged, and so forth. Anything they can’t see with the naked eye, but need to. You would think you would be able to see such surface defects with the naked eye, but if you’re dealing with unique engagement rings then you’ll need to look through every swirl, curve, and crevice and that’s not easy, so out comes the loupe.
Although loupes are used extensively by jewelers and jewelry stores, they are also available for sale to private individuals for a variety of reasons. Basically they come in handy if you need a closer look. If you have never looked at your diamonds under a loupe, consider trying it sometime. It can be fun and interesting to see the unique characteristics of your own diamond. However please remember that proper diamond grading can only be performed by a certified and trained diamond professional, also referred to as a gemologist.
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