Topaz has an exceptionally wide colour range that includes various tones and saturation's of blue, green, yellow, orange, red, pink, purple and most commonly brown. Colourless topaz can also be found, but is often treated by irradiation and heating to give it a blue colour. Topaz stones can be found in countries such as the USA, Mexico, Nigeria, Botswana, Madagascar, Afghanistan and Thailand. Quality factors of Topaz Colour Topaz is allochromatic, meaning that its colour is caused by imp…

The last Understanding Coloured Gemstones course of this year takes place on Tuesday 4th November. It is your last chance to book onto this informative training programme before the Christmas holidays begin. Tuesday 4th November 2014 (Only 1 space left!) £250 + VAT per delegate To download a booking form, please follow the link below: http://www.theassayoffice.co.uk/understanding_coloured_gemstones.html To book your place, call us on T: 0121 262 1024 or e-mail gem@thea…

Oral Historian: Fixed-term contract for 60 days over a three-month period.