It’s been around a longer than you think.
“3D prints with real gold are typically not produced on your average FDM printer. Though there are plenty of PLA filament brands on the market with gold color or even blends of real gold in them, these filaments produce models that don’t really look golden.
Instead, manufacturers have two ways of making gold 3D prints. The first is through direct metal laser sintering (or DMLS), which uses layers of powder and a laser to solidify the model, which is then extracted from the leftover powder. Post-processing cleans the model and polishes it to a beautiful golden shine.
The second is through lost wax casting. The process starts by using a high-resolution 3D printer to create a wax model, which then has plaster poured over it to make a mold. The wax is easily melted away, and gold poured in to create the final model, which is also polished after removal.”
Source: all3dp.com