I have over 2000 textures/materials and thought that I would share a few of them with you. Please feel free to use these however you like! Included are textures in 2048x2048 format including heightmaps and normal maps. I will be releasing more so let me know if you guys can use them.
Download Link: https://drive.google.com/file/d/0B6RgIttxWTdKQ0tVS09odFYxMjA/view?usp=sharing