Where do I go to get my tanzanite tested at a lab and certified in the UK?

Question

I need an official certificate.

Answer 1

Holts, 98 Hatton Garden, London, will certify any gemstone for a minimum fee of £23.50.

Telephone: [phone]

Answer 2

This is an interesting question. I see two problems - one in "testing" the mineral to be sure it is the mineral Tanzanite, and the other of getting someone to officially "certify" it as such.

The short answer is go to the web site for the www.Gem-A.info which is The Gemmological Association and Gem Testing Laboratory of Great Britain. They should be able to help you. (Note I found this site last. Read on if you have a wider interest in identifying your stone.)

The mineral Tanzanite is quite beautiful and has some rare properties. I particularly love it's pleochroic character - that it has slightly different colors when viewed from different directions. It was first discovered in Tanzania in 1967, and has become quite popular since the American Gem Trade Assoc. named it as another "official" birthstone for the month of December in Oct. 2002.

If I were still in school, I would try and use the geology department's micro-probe (or get someone who uses it regularly to do this for me). Basically a electron microprobe is a non-destructive analyzer of the atomic composition of a solid. Basically if you know the chemical composition, this instrument then determines the composition in terms of the elements from Be to U, and your see if the ratios of your Tanzanite match the composition the microprobe analyzed. Note - this could be expensive, I really don't know the costs here.

Another approach is to have a certified gemologist or jeweler study your specimen and use optical and other methods to determine it's identity. This is something geologists also learn, but only someone certified in the field can issue the document you are looking for.

As for jewelry appraisal service in the UK, I do not live there, but have tried to locate some that may have the necessary credentials to appraise your "Tanzanite." One thing to be careful of is to be sure your "gemologist" is certified in appraising other gem stones than diamonds. Much emphasis is given to the diamond appraisal and valuation, but you need someone who know the vast number of OTHER gem stones (and their imitations). As about their appraisal education or training in things other than diamonds before telling them you want them to certify your Tanzanite.

One I believe can do appraisals for insurance purposes is http://www.vandersay.co.uk/

Another way is to look at the listings of companies that certify gemologists. I found two such organizations -
Gemmological Association of Great Britain, and
Gemological Institute of America" which has some graduates in the UK. (see link below to email some of the GIA graduates -