Add google material Icons to "Tabs"

Can anybody help me with some HTML to allow me to add the google material-icons to the “tabs” as used in the “accordion” version?

I keep getting some strange results when I try!

Tabs that I am using

The type of icons I would like to use

Hey Roger,

What do the icons look like on the live app?

Hey Tim - they are not showing for some reason - but it manages to mess the text up - no doubt my awesome HTML skills need a tweak!