Howard Levine’s jewellery career started with pearls but changed to diamonds after nearly 14 years when he was asked to be the sales director of H. Chalfen Ltd. With Chalfen holding a reputation for being one of the finest manufacturers of diamond jewellery in the UK, he gained a great understanding of jewellery and the UK consumer. Whilst at Chalfen, Howard launched the UK's first B2B online diamond portal, started a successful branding for D colour diamonds and eventually became the managing director.

He left in 2017 to start Diamnet – an online platform that hosts over 1,000,000 diamonds – and was the first to add laboratory-grown diamonds alongside a natural diamond offering. He created a brand of jewellery called Hayes & Lake for Diamnet and is an officially recognised supplier to the CMJ. In addition to being a member of the London Diamond Bourse, Howard is honoured to sit on its council of management. He is also a member of the Diamond Expert Group with representatives from the NAJ, The World Federation of Jewellery - CIBJO, and the Natural Diamond Council.