This specific 3D model, "Emerald Art Deco Ring 3D print model 37", is an asset made available by "Unknown author".
You can download this asset for free at "Unknown platform" by following the link.
Usage of this 3d asset is subject to the "Unknown license" agreement.
STL (Stereolithography, filesize: 157 MB), 3DM (Rhinoceros 3D, filesize: 109 MB)