For example, in Ceylon, the rivers carry rubies and sapphires far from the original sites and deposits. By sifting and sorting the gravel beds all along the river beds and banks, then washing away the extraneous rock and gravel, miners find a few rubies and sapphire crystals a week. Panning for gold, gems, and diamonds in this manner is as old as mankind. One can spend a life time looking for the really large or significant find. Frequently, the key to finding gold or gemstones is to search where the ancient rivers used to flow millions of years in the past.
Many present hunters find gold and gem rough in sedentary rock.
Once a person has made a find of gem crystals, he sells them to another person who buys the crystals from all the miners working the rivers in the area. This buyer, when he has collected enough crystals to make it worth while, takes them to the large cutting centers. An expert planner at the gem cutting company then looks at each crystal over a high intensity light table. Most gems are graded wet, or with a side polished, so they may see inside the stone. The rough gems are then graded to size, color, and clarity.