Material Libraries....for both 2015 and 2016 Pro

I am wanting to carry over Materials Libraries from SketchUp 2015 Pro to SketchUp Pro 2016 Pro.
I can find the ones that I have added myself, but for the life of me I cannot find the ones that come with SketchUp.
Can someone please help me locate them. I am using a new MacBook Pro so keep that in mind.

Does anyone have some or know where to get some great photorealistic materials so I can add more to my library?

I would love to add materials from of the rendering packages. I already have Thea Render covered and SU Podium. Anybody know who else has great materials that can easily be added to SketchUp??? I do not necessarily want the renderers themselves as I am really happy with the ones I already have, but I am will to try them if they have a trial available.

Thanks so much for any and all help…

I believe pretty much the same suite of Materials are included with SU 2016 as with 2015 (though the folders were reorganized a little) so it should not be necessary to copy them. That said, for what it is worth, on Mac OS X they are located in

/Applications/SketchUp\ 201x/SketchUp/Contents/Resources/Content/Materials

You have to press control when you click on the app bundle and tell Finder to open the contents to get in there.

I’ll leave it to others to recommend other materials libraries they like. It depends a lot on what you want to model.