The Chalcolithic Age (5,500 - 3,000 BC) Originally the definition of the Chalcolithic period was clear. The beginning of the Chalcolithic age meant that humankind started using copper. The definition of the end, on the other hand, meant that the copper and tin are mixed to make bronze - hence Bronze age. However, later discoveries (e.g., Yumuktepe, circa 4300 BC) showed that before the Chalcolithic age started the humans were using copper. Also in the Chalcolithic period there was already experimentation to mix copper and tin. So the current definition of the Chalcolithic age seems to be out of date. It is also worth mentioning that, in addition to copper, use of stone and obsidian was common in this period. Obsidian is glass naturally forming around volcanoes when lava cools and solidifies fast before it crystallizes. Obsidian was used as a cutting tool in ancient times. Still in modern day it finds use as a cutting tool in some surgeries because of its superior sharpness compared to steel scalpel. Another distinguishing feature of this era was the sophistication in pottery making. Earthenware was decorated with variety of motifs (e.g., geometric) and paint was used in the process. The Chalcolithic artists spent their time mostly making monochrome and color painted pottery instead of drawing and painting the walls of the dwellings. As a continuation of the Neolithic era, terra cotta figurines of mother-goddess were common too. The Chalcolithic men used stone, adobe, and mud-bricks to build houses. They also learned how to use limestone for whitewash. The houses had stone foundations. The roofs, however, were flat. Beautiful metal tools attracted people who do not have them but have other valuable things to give, such as textile and ceramic. So trade started between people from different villages and tribes. Trade created new needs, such as keeping an inventory, making contracts between the traders. All these needs caused the invention of writing- not in Asia Minor though. Around 4,000 BC (the Late Chalcolithic period) the cities started to appear. Trading, the invention of writing, and relatively large size of population of human beings living in a close proximity were the beginning of the development process of modern societies that we have come to know now. Also circa 4,000 BC (the Late Chalcolithic age), migration to Asia Minor from the Balkans brought new people creating a heterogeneous cultural environment. Possibly, this development also helped promote the creation of modern societies. There were migrations from the Southeast too. And as in the rest of the history there were problems. During the droughts, for example, the tribes experiencing famine attacked and looted other tribes who had food. In the Early Stone Age, Asia Minor had the most advanced civilization. From the artifacts found it is known that the Chalcolithic men of Asia Minor interacted with the people in North Syria and Mesopotamia. However, towards the end of this period it lost its superiority. Egypt and Mesopotamia took the lead by improving trade and inventing writing. Asia Minor was a thousand years late in harnessing the power of writing. So at the end of the Chalcolithic Age the people of Asia Minor had a primitive life style compared to their neighbors, Egypt and Mesopotamia5. In the text the term "höyük" (mound) is used frequently. So it might be a good idea to explain what it means. In prehistoric times the dwellers of Asia Minor were building mud-brick houses on flat areas and lowlands, near rivers or creeks. When these houses were destroyed during earthquakes, wars, or just become unusable over the time, they were flattened and new ones were built on top of the previous ones. As the time passed the mounds were growing tall. When they reached 20-30 meters tall (66 - 98 ft.) climbing up and down used to become difficult so they were abandoned and new ones were built. Höyüks may reach to a diameter of 100 - 500 meters (328 - 1640 ft.). Since the new houses were built on top of the old demolished ones, they were in some sense recording the history, layer by layer over thousands of years. Since höyüks were dwellings of common people as opposed to the tumuli (tombs) of prominent individuals there are some main differences between höyüks and tumuli. Höyüks grow taller over a long period of time. If excavated, artifacts, such as common household tools, might be unearthed in its layers. Findings in the Hacilar settlement near Burdur and in Mersin-Yümüktepe area are some examples of the Chalcolithic age in Asia Minor. Among many other known Chalcolithic settlements in Asia Minor Nor#1untepe, Tepecik, Kalaycik, Kuruçay, Canhasan, Köskhöyük, Tülintepe, Korucutepe, Samsat, and Tilkitepe can be mentioned.