Display cases contain foot-high burgundy-velvet ziggurats displaying the tiny black carved-stone discs. Next to each one is a clay blob showing the impression each seal-stamp makes — spindly yet stately ibexes, vigorous shamans, or geometric patterns.
Placards explain that the seals were used to impress globs of clay onto the knots of tied bundles of trade goods, or onto a door meant to be kept shut. They were used to stamp palm-size clay "envelopes" containing marble-like tokens denoting numeric values of goods. The envelope's recipient would smash open this pouch to "read" the tokens.
The exhibit's most striking aspect is its revelation of the use of abstract symbols by a preliterate society. A cross within a circle denotes "sheep," and this figure with an added chevron, alluding to female genitalia, denotes "ewe." This semiabstract symbolism, connecting ancient literal pictographs to modern abstract language, marks the birth of writing.