This specific 3D model, "Chinese gold ingot 3D model 25", is an asset made available by "Unknown author".
You can download this asset for free at "Unknown platform" by following the link.
This specific 3D model is provided under the "Unknown license" framework.
STL (Stereolithography, filesize: 77.7 MB), OBJ (OBJ, filesize: 15.6 MB), MAX (Autodesk 3ds Max, filesize: 34.1 MB)