Indus seals

Form

The standard seal is a square of steatite, usually two to four centimetres across, with a perforated boss on the back. The face carries a single animal in profile above a short line of script, and often a small object in front of the animal usually described as a manger or a ritual stand.

Steatite is soft when quarried and hardens when fired, which permitted fine carving followed by a durable surface, and the seals were commonly coated with a white alkaline glaze.

The animals

The unicorn — a bull-like animal shown with a single horn, most likely a convention of profile rather than a mythical beast — is by far the commonest, accounting for the majority of known seals. Others show humped zebu bulls, elephants, rhinoceroses, water buffalo, tigers and gharials.

The horse does not appear. Neither does any securely identifiable scene of warfare, royal audience or conquest, which distinguishes Indus seal imagery sharply from Mesopotamian and Egyptian equivalents.

Function

Impressions in clay, sealings, have been found on bales, jars and door fastenings, establishing that the seals were used to mark and secure goods. The presence of Indus seals and Indus-style sealings in Mesopotamia and the Gulf shows they travelled with trade.

Whether they identify individuals, families, offices, guilds or commodities is unknown, since the inscriptions cannot be read. The distribution of particular animals across sites has been analysed for patterns without producing an agreed answer.

Scenes

A small number of seals depart from the standard form and show composite creatures, figures seated among animals, a figure in a tree, or a horned deity-like figure. These few pieces carry almost the entire weight of speculation about Indus religion, which is a great deal to ask of them.