Seals appear in the Indus Valley around 2600 B.C. with the rise of the cities and associated administrators. Square and rectangular seals were made from fired steatite. The soft soapstone was carved, polished, and then fired in a kiln to whiten and harden the surface. Seals made of metal are extremely rare, but copper and silver examples are known. The square seals usually have a line of script along the top and a carved animal in the central portion. The animals depicted on the seals, usually males, include domestic and wild animals as well as mythical creatures, such as the unicorn. A small feeding trough or mysterious offering stand is often placed below the head of the animal. Some seals contain more complex scenes that represent mythological or religious events. On the reverse side is a carved knob, or boss, with a perforation for holding a thick cord. These knobs must have been easily broken and are missing from most seals. The unicorn is by far the most common motif found impressed on clay tags originally attached to knots or binding on a bundle of goods. This suggests that the unicorn seal owners were mostly involved in trade and commerce but does not mean that they were the most powerful group. The less widely distributed seals with the bull, elephant, rhinoceros, and tiger motifs may have represented the most powerful clans or offices that actually ruled the cities. Other types of seals found in the Indus Valley, such as compartmented seals, reflect connections with regions where these types of seal were in use. Artifacts from the Indus Valley Civilization gallery of National Museum, New Delhi India. The Indus Valley Civilization (IVC) was a Bronze Age civilization (3300–1300 BCE; mature period 2600–1900 BCE) that was located in the northwestern region of the Indian subcontinent, consisting of what is now mainly present-day Pakistan and northwest India.[4]Flourishing around the Indus River basin, the civilization extended east into the Ghaggar-Hakra River valley and the upper reachesGanges-Yamuna Doab; it extended west to the Makran coast of Balochistan, north to northeastern Afghanistan and south to Daimabadin Maharashtra. The civilization was spread over some 1,260,000 km², making it the largest ancient civilization. The Indus Valley is one of the world's earliest urban civilizations, along with its contemporaries, Mesopotamia and Ancient Egypt. At its peak, the Indus Civilization may have had a population of well over five million. Inhabitants of the ancient Indus river valley developed new techniques in handicraft (carnelian products, seal carving) and metallurgy (copper, bronze, lead, and tin). The civilization is noted for its cities built of brick, roadside drainage system, and multistoried houses. The Indus Valley Civilization is also known as the Harappan Civilization, as the first of its cities to be unearthed was located at Harappa, excavated in the 1920s in what was at the time the Punjab province of British India (now in Pakistan). Excavation of Harappan sites has been ongoing since 1920, with important breakthroughs occurring as recently as 1999. There were earlier and later cultures, often called Early Harappan and Late Harappan, in the same area of the Harappan Civilization. The Harappan civilisation is sometimes called the Mature Harappan culture to distinguish it from these cultures. Up to 1,999, over 1,056 cities and settlements have been found, out of which 96 have been excavated, mainly in the general region of the Indus and Ghaggar-Hakra river and its tributaries. Among the settlements were the major urban centres of Harappa, Lothal, Mohenjo-daro (UNESCO World Heritage Site), Dholavira, Kalibanga, and Rakhigarhi. Source: en.wikipedia.org/wiki/Indus_Valley_Civilization