Use Microsoft Icons -Fabric Icons

On the following page you will find a list of all fabric icons Office UI Fabric is the JavaScript front-end framework for creating interfaces for Office and Office 365. Fabric provides visually-oriented components that you can expand, revise, and use in your Office add-in. Because Fabric uses the Office design language, Fabric's UX components look like a natural extension of Office. You can find a list of all icons here: https://uifabricicons.azurewebsites.net/ from Microsoft: