D.J.Sayer  F.G.A.  D.G.A.  F.J.V.A.
Since an  individually arranged guided tour with DeBeers underground, in the world famous Premier Diamond Mine at Cullinan, South Africa, John has travelled the world extensively researching gemstones including, Madagascan fancy coloured sapphire, rubies & jade from Burma, sapphire & spinel from Thailand, tourmaline, aquamarine, emerald & topaz from Brazil,  sapphire, tourmaline & moonstone from Sri Lanka.

Drawing on extensive experience in the world of antique jewellery, rare and unusual gemstones as well as all things gemmological / geological, John gained his F.G.A. qualification in 1976, followed by his D.G.A. in 1981 then became a National Association of Goldsmiths Registered Valuer in 1988. Consistent attendance at international seminars and conferences has kept Studleys Jewellers at the cutting edge of gemmological technology as well as extensive knowledge gathered throughout a wide-ranging career which has  enabled him to meet the strict criteria and have the knowledge required to become a Fellow of The Institute of Registered Valuers which was awarded in March 2009 at Goldsmiths Hall, London.
In early 2013 John received notification that he had been selected for  monitoring  of his valuation work by The Institute of Registered Valuers. The process involves submitting sample (anonymous) valuations undertaken in the past year. This is to ensure the professional standards recommended by the Institute are maintained. Needless to say, it involves much time and effort. To ensure absolute fairness and consistency, the submitted work is scrutinized by a panel of valuation specialists. John was notified in August 2013, stating that a Grade A had been attained (The highest grade possible) from the submitted sample valuations which are judged to meet the current criteria expected and required from a National Association of Goldsmiths Institute Registered Valuer. Therefore John retained the status of Fellow of The Institute Registered Valuers (FIRV). 

Once again in January 2018 John was selected for the monitoring process and in April 2018 received the results of Grade A, with 99% attainment of total marks with an added note stating his submission was superb. 

In 2020 The Jewellery Valuers Association was launched. This is a fully independent membership organisation for jewellery, watch and silver valuers in the UK & Ireland.

John is a Fellow of the of the Jewellery Valuers Association where continued professional development &  maintenance of of the highest professional achievement is required.