Gold - Part III
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Carlin-type deposits are not very well understood yet. It seems that these types of deposits are also formed by very hot water carrying gold up from deep in the earth. Unlike the other primary types of gold deposits, Carlin-type deposits are found in sedimentary rocks. Another unusual feature of Carlin-type deposits is: unlike other types of primary deposits where you can see the veins or gold running though the rock, Carlin-type gold veins are so small they can only be seen with a microscope. The gold bearing rock has to be crushed up and the gold collected by chemicals before it can be turned into usable metal. There is a lot of metal to be found in these types of deposits, but they have been overlooked in the past because people literally couldn’t see the gold.
Gold is a precious metal that has been forced up from deep in the earth and deposited in primary deposits called lode or igneous intrusion deposits. The primary deposits are broken down by weathering and erosion and carried away by water to either become placer deposits or Laterite deposits. For years and years people have been mining these deposits seeking the shiny precious gold. Only recently have people started to realize that there may be more gold out there, a lot more gold in Carlin-type deposits.