Generations of Chinese artisans have made lapidary contributions done through the centuries. The Chinese have specialized in exquisitely rendered miniature carvings made from colorless crystal, including vases, snuff bottles, ink boxes, incense burners, pendants, and figurines. Many other varieties of quartz have been utilized for the same purposes. However, no utilitarian object I've mentioned attracts more attention than flawless balls or spheres of quartz. Their manufacture dates far back into antiquity.
Small spheres are still quite popular today as gazing balls.
Any flawless quartz sphere over 6 inches in diameter is usually out of reach, monetarily, of the average person. We know little of how the ancient Greek or Roman lapidaries made these reading balls. However, the extremely laborious methods of the ancient Japanese are well documented. The stone was roughly chipped to a spherical shape with hammer and chisel, then rolled in an iron trough with water and sand until perfectly round. Emery powder was used in a similar manner to produce a satin polish.