$9 Realistic Granite Rock 03-250609 Low-poly 3D model by mega-3d. Available on CGTrader with 5000 polys and 2500 vertices. Check it out on CGHub.
OBJ (OBJ, filesize: 263 MB), FBX (Autodesk FBX, filesize: 132 MB), JPG (JPG, filesize: 132 MB), TEXTURES (Textures, filesize: 132 MB)