556 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1961 



examples of Chinese rock crystal. The production of flawless crystal 

 spheres for crystal gazing was a tour de force enjoyed by Chinese lapi- 

 darists. The crystal ball in the U.S. National Museum, which is 1278 

 inches in diameter and weighs 106% pounds, is the largest known flaw- 

 less sphere of this kind in the world. The quartz came from Burma 

 and required 18 months labor in China for the cutting and polishing. 

 Two fine crystal bowls of 17th-century Italian workmanship are shown 

 in the Morgan Library, New York, and there are many notable rock 

 crystal pieces in European collections [13]. Amethyst, which is a 

 violet-tinted variety of crystal, was occasionally cut into small vases 

 and dishes, but mostly it was used in antiquity for gems and beads. 



The hard cryptocrystalline forms of quartz like chalcedony, agate, 

 carnelian, prase, and jasper have also been widely used by lapidarists 

 for carving small figures, ornamental vases, and seals. They differ 

 only in the fineness of their crystalline structure and translucency and 

 in their color, which is caused by impurities — chiefly oxides and sili- 

 cates of iron and manganese. 



Carnelian was a favorite medium of the cylinder seal makers of 

 Babylon and Assyria. A. Lucas tells us that it occurs abundantly in 

 the eastern desert of Egypt and was much used from predynastic 

 times onward for inlay in jewelry, furniture, and coffins [14]. It 

 was so highl}'^ valued that in later times an imitation carnelian con- 

 sisting of translucent quartz set in red cement was often employed to 

 supplement the genuine article as inlay. There are some striking 

 white agate dishes ornamented with orange-red carnelian flowers cut 

 from a single stone in the Bishop collection of the Metropolitan Mu- 

 seum of Art. Carnelian and amethyst were sought after in ancient 

 Egypt for making bead necklaces, although drilling of the holes in the 

 beads must have required nearly inexhaustible patience. 



Agate, especially banded agate, is another excellent lapidary ma- 

 terial, and even the purely functional agate mortar found in most 

 present-day analytical chemical laboratories can be a work of art. 

 One of the most notable ancient objects in agate is the carved vase 

 once owned by the great painter Peter Paul Rubens, which is now one 

 of the showpieces of the Walters Art Gallery in Baltimore (pi. 4, fig. 

 1). According to Marvin Chauncey Ross, "It is a vessel over seven 

 inches high carved from a single mass of agate, shading from a warm 

 honey color to a milky white. The ornamentation is carved in very 

 high solid relief thus adding some strengtli to the walls of the vase, 

 which are worked to the thinness and translucence of porcelain." 

 [15.] Rubens strongly admired the vase which Ross believes dates 

 from the fourth or early fifth century A.D. and is Byzantine in origin. 

 An engraving of it in the Berlin Print Cabinet is made after a drawing 

 in Rubens' own sketchbook. 



