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Ref: spectra


Gem ID Book £25.00 instead of £29.50 £ 25.00

Gemstones book £15.00 £ 15.00

Fine-focus pen torch £5.50 incl. VAT £ 5.50 incl. VAT

Price: 35.00 (Including VAT)


Spectroscope (diffraction grating type), 50mm long X 12mm dia.

You view the light from coloured stones, you see a spectrum of colour (rainbow) interrupted with black (or white) lines*. You don't take any measurements (this is not a measuring spectroscope), you just have to recognise the patterns of lines.

If you don't have any gemstones to hand, here's some fun things to do with a spectroscope. Point it at the sky and see the lines that correspond to hydrogen burning in the sun and oxygen being absorbed by the atmosphere. Point it at a fluorescent light and see the dozens of lines caused by the gases burning. Shine a torch through your finger, see the pattern of lines caused by iron in your blood.

* This is because some elements (transitional elements) absorb specific wavelengths (colours) of light, appearing as black lines; some re- transmit specific wavelengths, appearing as white lines. These patterns of lines give clues as the chemical composition of the stone.

{Is it easy to use?}

No. It can be fiddly, holding the stone, a light (e.g. small torch) and the spectroscope, all at the correct angle to view the colour.

If you like colours and are good at recognising patterns of lines, you'll love this tester. Get to recognise the patterns of lines that indicates chromium and iron, instantly identify blue manamde stones (cobalt-blue), see the myriad of lines in some zircon caused by radioactive decay. But if you have no sense of colour whatsoever (like me!) then patterns of lines in a spectrum will totally confuse you.


It works by looking at the colour of a stone, so the stone must have colour.

Usually you would shine a light through a transparent stone, but you can examine opaque stones by 'bouncing' the light off the surface of the stone into the specdtroscope, but this is difficult, especially if the stone doesn't have a strong colour.

{Further information}

This is a standard gem tester used by gemmologists, it does not come with instructions, you are expected to know how to use it (a bit like a bicycle, it does not come with instructions telling you how to ride it).

If you are new to gemmology I strongly recommend the book Gem Identification Made Easy. This book systematically works its way through all the optical testers, telling you the theory behind them, what they will test, and how to use them. To get your discount tick "Add the Gem ID book" when you order the spectroscope.


Here are more details of the optional extras you can add to this order:

Gem Identification Made Easy £25.00 instead of £29.50 if you tick 'Add the Gem ID book' when you buy the spectroscope.

Not as detailed, but good guide to gemstones, beautifully illustrated, is Gemstones.

A good light source is essential for using optical gem testers, the fine-focus Pen torch.