"One must lead by example, by simply teaching his or her family history and love from time to time, to maintain the unity the family has inherited."
The circles are the lines of generations coming down, passing heritage from one to the next.
All of Antony's pieces are beautifully finished and he rarely uses the common Zimbabwean technique of contrasting rough and smooth textures. Perhaps when your finishing is so good, you are wise to play to your strengths!
Cobalt stone is the local Zimbabwean name given to this type of serpentine; it does not, as far as we know, contain any cobalt.