10X18 with 20X12 Loupe (both triplets) More sophisticated diamond gauges it works on nickel providing

it works on nickel providing the nickel hasn't be processed with a coating

A refractometer measures refraction (bending) of light as it passes through the gemstone (like poking a stick into clear water)

UK power supply for mains operation

chfilt is the original English filter

as will some spinel

10X18 with 20X12 Loupe (both triplets) More sophisticated diamond gauges it works on nickel providingSummary A 10X magnification lens folds out from on end (18mm diameter); 20X from the other end (12mm diameter). Too see reviews of loupes, click here and then scroll down to see the difference between this and an identical looking loupe at a fifth the price. Detail A 10X magnification lens folds out from on end (18mm diameter); 20X from the other end (12mm diameter). Best quality. I always say that a good quality 10X loupe is better than a 20X loupe