AstleyClarke.com was established in 2006 by the former Tesco.com employee; it offers customers in Europe, the US and Middle East access to more than 50 bespoke jewellery brands.
Celebrity clients include Nicole Kidman, while busy City bankers are also said to like the same day delivery service offered by the company.
“Index brings with them exceptional expertise in the online arena which we look forward to applying to the luxury space," Clarke says.
"Our vision at AstleyClarke.com is to build a hugely stylish luxury brand online. Our aim is to be selling more designer jewellery online than traditional jewellery brands such as Tiffany."