In its size, state of preservation, and fineness of execution, this piece has few parallels in Islamic relief-cut glass. The decoration consists of a band of palmettes, half-palmettes, and floral motifs on two scrolls between two horizontal ridges. Early Islamic carved rock-crystal vessels reputedly produced in Egypt demonstrate a close similarity in technique and design.
Inevitably, the immediate models used by Iranian glassmakers following the advent of Islam came from their Sasanian heritage, which in turn had developed from a centuries-long distinctive and individual artistic tradition in the geographical area of Greater Iran. Under Islam, this approach was raised to new heights with the production of transparent, almost colorless cut glass, which was decorated with the aid of a rotating wheel, thereby treating the material more like stone instead of taking advantage of its great malleability when hot. Once a colorless batch had been created (by decolorizing the glass with the appropriate oxide of manganese), a thick-walled "blank," roughly in the shape of the required vessel (usually either an open bowl or cup or a globular bottle with a narrow elongated neck), was blown either freely on a blowpipe or into a dip mold. After it cooled down to room temperature, the blank was transferred to another area of the glass workshop or, more likely, to an entirely different workshop that specialized in glass- as well as stonecutting.
For both objects (MMA 65.172.1 and 1974.45) presented here, this was the common origin. The artistic intent and therefore the final results, however, appear to be very different when the two works are compared.
The small cup (MMA. 65.172.1) is solid, perfectly balanced in the distribution of its weight and its decoration, and sits comfortably in the hand. Its pattern is executed in high relief and looks decidedly to earlier models: the pointed petals or leaves that arise from the center of the base are strongly reminiscent of designs used in Iran during Achaemenid times (sixth–fourth centuries B.C.). The socalled omphalos disks (Greek for "navel," thus termed because of the central protuberance), arranged into two staggered bands, represent one of the most popular and successful patterns from Late Antiquity through the early Islamic period. Clearly this object was a valuable drinking vessel made in imitation of the more precious and expensive rock crystal. Once the cup was empty, the drinker would place it upside down to rest on its flat rim, revealing the attractive floral pattern around the base.
When handled, the beaker (MMA 1974.45) creates almost an opposite effect: it is weightless and appears to be very fragile. Its decoration is dynamic and light, and the beaker itself seems insubstantial to the point of creating a sense of trepidation in the person who holds it. Indeed, it is almost a miracle that, though broken and repaired, it has survived virtually complete to this day. The skill of the glasscutter who was able to create patterns on its surface is astonishing. He not only reduced the thickness of the walls to about 3/64 inch (about 1 mm) while avoiding breakage, but also produced the relief decoration with a thickness of less than approximately 5/64 inch (2 mm). An ideal point of reference for the viewer is provided by the lower ridge, which protrudes for 3/32 inch (about 2 mm). Combined with the excellence of its cut decoration—a six-unit repeat design of palmettes, half palmettes, and calyx motifs, linked with a scroll arranged horizontally around the circumference—these qualities establish this drinking vessel as one of the very few surviving masterpieces of relief-cut glass from the first millennium A.D. Although it has been attributed to both Iran and Egypt (the latter particularly because of strong connections in technique and design with celebrated Egyptian rock-crystal vessels), there is little doubt that the beaker represents one of the highest points of Iranian glasscutting. The identification of rock-crystal cutting traditions in the eastern lands of the Islamic world, which is corroborated by the appearance on the market in recent times of objects with an Iranian or Central Asian provenance, further validates the Iranian origin of this splendid beaker. 
Stefano Carboni in [Ekhtiar, Soucek, Canby, and Haidar 2011]
1. Most recently, by David Whitehouse in Carboni et al. 2001, pp. 172–73, no. 79.
2. See, for example, Kröger, Jens. "Crystal, Rock.ii. In the Islamic Period." In Encyclopaedia Iranica 1985–, vol. 6 (1993), pp. 440–41; or in Encyclopaedia Iranica, Online Edition, December 15, 1993, available at http:// www.iranica.com/articles/crystal-rockbolur- bolur-e-kuhi. To my knowledge, no specific study has been published on the subject; the largest number of rock-crystal objects of eastern Islamic origin is in the Dar al-Athar al-Islamiyya, al-Sabah Collection, in Kuwait City.
[ Saeed Motamed, Frankfurt, by 1973–74; sold to MMA]
New York. The Metropolitan Museum of Art. "Glass Gathers: The Hagop Kevorkian Fund Special Exhibitions Gallery," May 24, 1990–March 31, 1991, no catalogue.
Corning, NY. Corning Museum of Glass. "Glass of the Sultans," May 24, 2001–September 3, 2001, no. 79.
New York. The Metropolitan Museum of Art. "Glass of the Sultans," October 2, 2001–January 13, 2002, no. 79.
Athens, Greece. Benaki Museum. "Glass of the Sultans," February 20, 2002–May 15, 2002, no. 79.
Ettinghausen, Richard. "Islamic Art." Metropolitan Museum of Art Bulletin vol. 33, no. 1 (Spring 1975). ill. p. 4 (color).
Swietochowski, Marie, and Marilyn Jenkins-Madina. Notable Acquisitions 1965–1975 (1975). p. 146, ill. (b/w).
Jenkins-Madina, Marilyn. "Islamic Glass: A Brief History." Metropolitan Museum of Art Bulletin vol. 44, no. 2 (Fall 1986). p. 27, ill. fig. 26 (color).
Welch, Stuart Cary. The Islamic World. vol. 11. New York: The Metropolitan Museum of Art, 1987. p. 17, ill. pl. 6 (color).
Dodds, Jerrilynn D., Dr., Oleg Grabar, Antonio Vallejo Triano, Daniel S. Walker, Renata Holod, Cynthia Robinson, Juan Zozaya, Manuel Casamar Pérez, Christian Ewert, Guillermo Rossello Bordoy, Cristina Partearroyo, Sabiha Al Khemir, Dario Cabanelas Rodriguez, James Dickie, Jesus Bermudez Lopez, D. Fairchild Ruggles, and Juan Vernet. Al-Andalus: The Art of Islamic Spain, edited by Dr. Jerrilynn D. Dodds. New York: The Metropolitan Museum of Art, 1992. no. 4, pp. 43-45, ill. (color).
de Montebello, Philippe, and Kathleen Howard, ed. The Metropolitan Museum of Art Guide. 6th ed. New York: The Metropolitan Museum of Art, 1992. p. 313, ill. fig. 4 (color).
Carboni, Stefano, David Whitehouse, Robert H. Brill, and William Gudenrath. Glass of the Sultans. New Haven: Yale University Press, 2001. no. 79, pp. 172-173, ill. p. 173 (color).
Ekhtiar, Maryam, Sheila R. Canby, Navina Haidar, and Priscilla P. Soucek, ed. Masterpieces from the Department of Islamic Art in The Metropolitan Museum of Art. 1st ed. ed. New York: The Metropolitan Museum of Art, 2011. no. 18, pp. 40-41, ill. p. 40 (color).