Im presuming your putting water into the cell and freezing it?
The water will freeze on the exposed surface first, this is why air bubbles are trapped inside ice cubes, what you need to do is to place the cell in a coolant of some sort to freeze the bottom first then slowly submerge the cell to freeze from the bottom up to allow the water to expand upward to the open section of the cell during expansion due to freezing. Simply placing the water filled cell in the freezer will cause top down freezing and hence break your quartz cells, you need to make the water freeze bottom up. Try somethin like what i have described.
-Josh