https://www.cgtrader.com/3d-print-models/art/scans-replicas/el-corazon-romancing-the-stone
El Corazon, dimensions (stone): 98.74 x 106.15 x 41.81mm (as saved) or 3.89 x 4.18 x 1.65in
Scale up or down as needed but its pretty close to the prop size. Just rember to scale both equally if you make changs so it still fits the stand correctly.
Each piece is 250k poly
If you need any help with the file let me know.
Based on the Emerald from Romancing the Stone albeit with a few more facets.