My kids are huge fans of the Dragon Masters stories. In the novels each child has a “Dragon Stone” that they wear around their neck. They are normally a green color. I made this model in TinkerCAD in about 2 min so it's nothing fancy, but it should be find for some 6 and 7 year old kids to pretend to be dragon masters.
Its not a complicated model, so bigger layer heights will save you time, but these are the settings I used.
Layers: 0.20 mm layer height
Supports: You might want supports, but I found that with 3 perimeters on the vertical shell, it prints fine without supports.
Infill: I used 15% “Support Cubic”.
Others: I would also recommend disabling “ensure vertical shell thickness” seems unnecessary and adds about 30% to the print time.
After I printed it i used a gold paint sharpie to color the band gold.
The author marked this model as their own original creation.