This is Turkish stick agate which comes from Çubuk City located 20 miles north of Ankara. Curiously the word Çubuk in Turkish means stick although the city was named long before these agates were ever discovered there. 

Stick agate owes its fascinating patterning to zeolite which completely gave up its columnar form to silica creating a seemingly endless variety of evocative designs. Each and every piece is totally different.

This sphere was handmade by local talented Lapidary artist, John Daly.