Rock type/friction beta?

Hey,

So one thing that I really enjoy about climbing is how the type of rock affects how you have to climb in a particular area. Knowing the rock type also helps for planning a trip in terms of necessary gear, shoes, etc. Has anyone considered adding a "rock type" flag for each climbing area? Could be as simple as sandstone, granite, etc, or there could even be a qualitative friction scale. Can I smear my way up, or is it time to bust out the aggressive edging shoes?

This is addressed in the description of the area.

It often is, but not always. For example:
mountainproject.com/v/jacks…

Plus, a subheading would be easier/faster than reading through the whole area description. Maybe I'm alone on this, but with a lot of the smaller Midwest crags, I often look for a particular rock type (e.g: sandstone), as the alternative is usually slick, chossy limestone. It would be cool to be able to see and search by rock type from the main map.