About Our Team

We are a team
of expert jewellers

SellDiamondJewellery.com are retail partners of The GemLabW4, West London’s local, reliable and trustworthy gemstone analysis laboratory and jewellery valuations centre.

Staffed by fully qualified gemmologists and diamond experts with a combined trade experience of over 50 years and countless qualifications.

The GemLabW4 specialise in Gemstone identification, jewellery valuations, scrap gold purchase, pre owned jewellery purchase  as well as the vital diamond assessment for SellDiamondJewellery.com.

If your diamond needs assessment the specialists at The GemLabW4 will independently grade, assess and report on your precious gem in order to make you the best cash offer possible.

Assessments can usually be carried out same day and should you accept the offer cash can be transferred to your bank within 24 hours.

Simon Johnson

Simon Johnson Bsc Hons

After doing his diamond grading training with The Diamond Trading Company (formerly DeBeers) in 2005 Simon Opened Marmalade Fine Jewellery offering bespoke jewellery for his clientele in Chiswick.
As he says – ‘creating beautiful things for happy people’.
The shop soon gained a great reputation and has won several national awards over the years. In 2016 Simon was elected Chairman of the National Association of Jewellers and spent 2 years leading the countries only Jewellery Association through significant and important changes. Stepping down in 2018 to concentrate his efforts on building TheGemLabW4.

Janina Brown BA Hons, FGA, DGA, MIRV, PJ Dip

Janina is a certified gemmologist (FGA and DGA), member of both the Gemmological Association of Great Britain and the Institute of Registered Valuers. She has always enjoyed a passion for jewellery and gemstones and was encouraged and supported by her employers at Marmalade Jewellery to build on her experience and achieve the relevant qualifications to become a registered valuer. Janina studies recent gemstone treatments and regularly attends conferences and seminars within the trade to keep her knowledge current.

Lucy Jupp BA Hons, P.J Dip

After successfully completing her Foundation in Gemmology in 2018,
Lucy is now working towards her full FGA Diploma.
Her passion for jewellery and gemstones as a young child has led her
into a career in the jewellery industry with a special interest in Antiques and Vintage jewellery.
Lucy hopes to continue her training with the DGA diploma and Registered Valuers course.