Commodity market in Sumer between 4500 BC and 4000 BC. Sumerians first used clay tokens sealed in a clay vessel, then clay writing tablets to represent the amount—for example, the number of goats, to be delivered. These promises of time and date of delivery resemble futures contract. Early civilizations variously used pigs, rare seashells, or other items as commodity money. Since that time traders have sought ways to simplify and standardize trade contracts. Gold and silver markets evolved in classical civilizations. At first the precious metals were valued for their beauty and intrinsic worth and were associated with royalty. In time, they
Aurum Geyser decreases and increases its interval at regular times during a week. Eruptions last about 90 seconds and range in height from to . An eruption is usually preceded by bubbling in two small vents nearby. On rare occasions, an eruption will be followed by a second smaller eruption 5 to 10 minutes after the primary eruption. Aurum Geyser Aurum Geyser is a geyser in the Upper Geyser Basin of Yellowstone National Park in the United States, on Geyser Hill. Aurum can, at times, be very predictable. Other times it can be very erratic. Observations have led to the theory that