coloured precious gemstones
Holts Gems, 1st Floor, 39 Greville Street, London, EC1N 8PJ.
Mon to Thurs 10am-5pm Fri: 10am-4.30pm
Gemstone expertise since 1948, Holts Gems specialise in bespoke and gemstone-set jewellery and lapidary insurance valuations.
World Gemological Institute
14 Greville Street London EC1N 8SB
Mon-Fri 9.30am to 6.00pm
For over the past 30 years the World Gemological Institute (WGI) have build a solid standing reputation as one of the leaders in the Industry.