Ice (Wikipedia)
Ice is water that is frozen into a solid state, typically forming at or below temperatures of 0 °C, 32 °F, or 273.15 K. It occurs naturally on Earth, on other planets, in Oort cloud objects, and as interstellar ice. As a naturally occurring crystalline inorganic solid with an ordered structure, ice is considered to be a mineral. Depending on the presence of impurities such as particles of soil or bubbles of air, it can appear transparent or a more or less opaque bluish-white color.- Chalcolithic (Wikipedia)
The Chalcolithic (also called the Copper Age and Eneolithic) is an archaeological period characterized by the increasing use of smelted copper. It follows the Neolithic and precedes the Bronze Age. It occurs at different periods in different areas, and is absent in some parts of the world, such as Russia. Stone tools were still predominantly used during this period.
- Old Coast, New Coast: Doha, Qatar (hakaimagazine.com)
In the Neolithic, 10,000 years ago, this entire shore would have been underwater. At that time, the coastline was two meters higher. This wet period brought the first known occupation of Qatar and archaeologists occasionally find the dark brown rock tools of the people who took advantage of this brief climactic window—and the concurrent flourishing of life—to spread across Arabia.