The 10X Loupe Standard For Evaluating Gems
Loupes come in several varieties.
Watchmakers prefer the kind held by the eye socket.
Other professionals prefer loupes worn like eyeglasses or clipped onto glasses.
Some types sport fancy features like illumination and built-in tweezers.
Jewelers and Gem Dealers prefer the hand loupe.
For gemologists, the 10X loupe (with ten-power magnification) is the standard for hand-held gem identification.
It's important to note that the degree of magnification for clarity grading has been specified to the international standard of 10X. The magnification should not be greater or the stone might be down-graded, neither should it be lower otherwise the gem could be wrongly up-graded.
Although you’ll find more powerful loupes, the depth of field (the area that’s in focus) is so small above 10X that they’re hard to use. Instead, use a microscope when you need higher magnification. With lower-powered magnification, you just can’t see as much detail.
You may encounter the following terms when shopping for a 10X loupe.
Triplet: a loupe with three lenses, which reduces distortion around the edges.
Color correction: a special lens coating to ensure you see natural colors, not colors distorted by passing through the loupe.
These features increase the price.
The standard for judging diamond quality is what an expert can see in good lighting with a triplet, color-corrected 10X loupe. Gemologists use this same standard for evaluating colored stone quality, too. However, you don’t need to purchase such an expensive variety for your gemological studies. You can get as much information and enjoyment from a less expensive model.
JDMIS lessons
コメント