I have settled on 9gr - 10gr Magnesium.
If I were happy to go a little heavier the Audio Technica AT-LH13/OCC.
Produced from TechniHard which is AT’s version of a composite metal known as (Duralumin). Duralumin is known for the properties of managing transferred energies, it is sought for use in place of many other metal composites.
I am lead to believe the Anodised Coating is a Diamond Like Coating, that has improved properties, due the hardness on the surface for dissipating transferred energy.
The Signal Path is well thought out too, as it offers PC OCC Pins to be connected to.
Purchase some PC Triple C Tag Wires and the assembly in use, to support the Cart’s Mechanical and Electrical Interface is a good place to start, most likely a Keeper, when this Headshell Weight is usable.