These gemstone refractometers are offered either as a compact professional or standard version. They both provide a sharp image and good readability, and have the option to select LED illumination or ambient light with a sodium filter.
Gemstone refractometers are used for the classification
and quality control of gemstones. The gemstone is simply placed on the prism with a drop of
contact fluid. The refractive index of the gemstone is read
through the ocular of the refractometer. The refractive
index is an important parameter in classifying a mineral
Each mineral has its typical refractive index,
due to its chemical composition and crystalline structure. Gemstones with a high RI are generally more brilliant, ie a diamond has a RI of around 2.4, whereas quartz approximately 1.55.
Our gemstone refractometers are characterised by their
particularly sharp image and good readability.
With the sodium filter that only lets through light with a
wavelength of 589 nm, the refractometer can be used as
a mobile unit with an ordinary light source or with
sufficient ambient lighting. LED illumination is also
available with a wavelength of 589 nm.
Both gem refractometer models are constructed of cast aluminium, and are supplied complete with a polarisation filter and manual.