There's a toolkit of icons that's currently not published, but it's too large for me to upload here. Can you please reach out to me at esnyder@splunk.com and I can send it to you?
There's also a good non-standardized set of icons here: https://www.material.io/resources/icons/?style=baseline
Can you be more specific? Are you talking about glass table icons?
Right - glass table icons - thank you.