Not sure if this is what you need. This is what I found in our materials folder.
I also curious to know if there's a website, where anyone can go and download material properties (that have been validated)?
I am willing to share all of material properties files, but I can't say that I have validated everyone. I seem to remember there was a post on this topic long ago. One of the things I am push here is making everyone select a material file when they create a start_model. My concern is what if the material they want to use in not in the library? They can assign any existing material and change it later on, but I have a feeling that I will get slammed with all the request for material properties later. Maybe this is the forum where we can post and request this community to share what they have on their system.