Iron was favored over bronze throughout history because it could be formed into thin and detailed structures which could not be achieved when casting bronze. This is important because it meant that iron blades could be worked and therefore sharpened to a much more refined degree than bronze which was brittle. Iron is also more readily found, a metal which could be found locally around the world and did not depend upon an immense, trading network. By 400 B.C., iron tools and iron objects became ubiquitous throughout various civilizations with the effects of this new technology felt upon the cutting edge of agricultural technology. Iron is more practical than bronze as bronze needs to be melted down and recast if broken in opposition to iron which could be taken to a fire, hit with a hard object, and repaired to the point at which it becomes functional once again. These aspects helped iron to gain favor worldwide as the metal of choice for building and advancing society. As the Iron Age progressed, knowledge about where iron deposits are found became better understood with more and more iron becoming available upon the open market. This is important because the more readily available a particular type of artifact is, the younger the item typically presents as. As time progressed, iron became akin to plastic of the modern day, being cost effective and readily available to manufacture virtually anywhere. Iron tipped wooden plows allowed for more difficult soils to be farmed, which meant that more land could be cultivated making iron truly an agricultural and commercial revolution in the ancient world. Despite lasting for a period of 1000 years, the Bronze Age was quickly replaced with the more effective and efficient Iron Age. The issue of total replacement is complicated as bronze was not only used for tool making, it also helped to create an elite class and was used for spiritual and ceremonial objects as well as visual displays of prestige and wealth. Iron tools several hundred years later, failed to achieve the same intrinsic value within society that bronze once had as it was less rare and precious and therefore less valuable. Iron tools however were highly practical unlike their bronze counterparts, a feature which plagued agriculture and society as a whole