Portable Refractometer Gem-A - TR612

A portable unit supplied in travel case. Features built in monochromatic & polaroid filter. Adjustable eyepiece for ease of focus. Range from 1.30  to 1.79.

A refractometer is used for measuring the refractive indices of transparent and opaque gemstones with a flat polished surface or crystal face.

This instrument can also be used to test cabochons via the distance vision technique. Stones which are set within jewellery can be tested with great care if the setting allows this.

The range of the refractometer is from 1.30 to 1.81. The error in measuring faceted stones is not abouve 0.0005 and for cabachon stones is 0.01.

With many flat polished stones, it is possible to determine whether a stone is optically isotropic (and thus singular refractive) or anisotropic (double refractive).

This refractometer gives the refractive index of an isotropic gemstone and also the maximum and minimum refractive indices of an anisotropic gem, the birefringence of an anisotropic gemstone and whether an anisotropic gemstone is optically uniaxial or biaxial (or optically positive or negative).

This refractometer gives highly accurate readings +/- 0.003. The unit has a built in monochromatic filter and is supplied with a removable polarising lens.

The eyepiece has a threaded system so that the focus can be adjusted to the users eyesight.

It has a wide prism glass, stainless steel faceplate and a travel case.

Please note that this unit requires (Additionally Not Supplied) -

An External Light Source (SKU TL52) and Refractometer Fluid (SKU TZR61).