This small wooden sphere, c1770, is about the size of a ping-pong ball. Made of polished walnut, it has a small mother-of-pearl disk inlaid on the top. It is bisected in the middle, as it is two pieces screwed together. When unscrewed, it reveals it miniature powder puff.
The puff is made of marabou, attached to purple velvet which surrounds a tiny ivory handle. There are still remnants of powder at the bottom of the box.
This type of powder puff is seen in many paintings of the 18th century, especially French paintings, where a woman is seated at her dressing table. The powder puffs are, of course, much bigger, but they are constructed just as this one is, with marabou attached to an ivory handle.
I suspect this little powder box was part of a traveling set, ie a cosmetic case. Face powder at this time generally had a talc base, but with additions of ingredients such ground pearl, rice powder, arrowroot powder, and fragrance.