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Is it true that emeralds are formed when two continental plates hit each other?
Question Date: 2018-03-09
Answer 1:

Not directly.

Emerald is a form of the mineral beryl, which contains beryllium, aluminum, oxygen, and silicon. Beryllium is a fairly rare element because it is destroyed, not created, in stars, which is why beryl is a rare mineral and all of its varieties are also gemstones (others being aquamarine, morganite, and heliodor).

Emerald is most commonly found in slow-cooling granites, rocks that crystallize from magma kilometers below the surface while volcanoes erupt above them. These can happen where continents collide with each-other, but more often when a continental plate collides with an ocean plate , instead of another continental plate. This is happening today in places like the Cascades, Japan, Java, the Andes, and many other places. Because the Earth's tectonic plates move and because of erosion, the place where emeralds are found now tell you where these volcanic arcs were in the past, not where they are today.

Answer 2:

Emeralds often form when rocks have been baked at high temperatures or squeezed to high pressures. When two continents collide then that produces a lot of pressure, which can help form emeralds.

So there are emerald mines in places like Afghanistan where continents have collided. But emeralds can also form in other places as well, such as with other minerals which crystallize inside an empty space under rock.



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