How do you find emerald in layers of sediment?

Answer 1

In general, sediments are set down by the deposition of all manner of "stuff" in water that "precipitates out" and settles on the bottom. Could be inorganic like fine dust from eroded rock. Could be organically created like marine shells. Could be layers of plant material. Whatever. Over time, an appreciable "thickness" of material is deposited. Then more, and more. Sometimes the composition changes a bit here and there, sometimes not. But you get the picture. Over geologic time, the layer(s) are compressed and harden to form sedimentary rock. No where in that equation does the emerald appear. Emeralds are born of "granite-type" rocks, and will be found there. It is possible that erosion of emerald-bearing ganitic pegmatites (which is where they live) may put some in estuaries, but to look for them generally requires mining in the traditional sense. Except for the ones created in the laboratory, which was happening at least as long ago as the 1960's. A link to the Wikipedia article on the emerald is provided. Surf on over and check out the pics.