My fairly new quartz kitchen worktops don't seem as shiny now as they should be; so far I've just been cleaning them with a water spray with a few drops of fairy liquid in it (as advised by the installer) and e-cloths. I'm very wary of using anything that might not be suitable for quartz surfaces (they cost a small fortune!), so would appreciate advice and/or recommendations for any tried and tested products that will restore the worktops to their shining glory...