Often have community-created texture packs.

If you can tell me what you're using (e.g., Blender, 3ds Max, Unity) or what kind of stones (e.g., gravel, pebbles, castle walls) you need, I can find a similar, safe, and free alternative.

Search for "Stone Set" to find downloadable 3D models and textures.

High-quality, scanned stone assets available via Epic Games.