Measure units are millimeters, it is about 24.4 mm in diameter.
Mesh is manifold, no holes, no inverted faces, no bad contiguous faces.
Two version of the model is available:
1) Tr_Pndnt (.blend, .stl, .obj, .fbx) This files contains two object the pendant itself and a bail. 470150 triangular faces.
2) Tr_Pndnt_prts (.blend, .stl, .obj, .fbx) Here is parts before boolean operations: The bail, 5 loops, round frame, scrollwork(as one piece). 506392 triangular faces.