Thanks a lot. For those who try to create a sphere, below is attached the devices or accessory in the form of a link so that everyone can make spheres of stone or some other mineral using a Dremel multitool and a hand drill.

Devices used:
Diamond tip thick concave ball head: https://amzn.to/3NHXYn2
Thick concave diamond tip: https://amzn.to/48hEb64
Concave Diamond Tip all measurements: https://amzn.to/3RKLNqw
Small concave diamond tip for dremel: https://amzn.to/3vn80n9