Rock Crystal Cosmetic Bottle 9th-11th century A.D. A rock crystal bottle of globular form, stepped shoulder, pyramidal neck with three notched vertical bands. 10.9 grams, 24 mm (1 in.). Acquired before the early 1970s. Ex London, UK, gallery. Property of a London gentleman. Rock crystal was one of the most treasured materials at the Fatimid court. Imported from afar, the material was endowed with magical properties. Because of the hardness of the material, carving such smoothly beveled vegetal designs in rock crystal required tremendous skill and patience.