This item is a very usual covered bowl. It is made of crystal and when the pointed lid is on it looks almost like a teardrop or maybe an acorn. The bowl is clear glass and the lid is clear glass at the top and frosted glass at the bottom. The clear glass on both pieces is ridged. The bowl has a V on the sides and the lid has a point on the sides that fit in the V. This lidded bowl measures approximately 6" tall (to top of point on lid) and 5" across.
It really is a beautiful and unusual piece. I don't know how old it is or much more about it but will try to answer any questions you may have.