This specific 3D model, "Emerald Solitaire Ring 3D print model 44", 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: 11.5 MB), 3DM (Rhinoceros 3D, filesize: 11.4 MB)