Diamond mining in BrazilThe diamond mines in Brazil are quite interesting. Diamonds are carried to E

Diamond mining in BrazilThe diamond mines in Brazil are quite interesting. Diamonds are carried to Earth’s surface in a type of volcanic eruption never seen by humans called a kimberlite. These eruptions form deep in Earth’s mantle and carry crystals, including diamonds, up from several hundred kilometers below the Earth’s surface.Those eruptions create vertical pipes when they reach the surface. To mine diamonds from these pipes cheaply, the best technique usually is to dig almost straight down, limiting the amount of extra weight moved out of the way leading to incredibly deep holes in the ground like the Mir mine (http://tmblr.co/Zyv2Js1VUXqS4).The mines in Brazil are still finding diamonds that came up in kimberlite pipes but the eruptions took place oover a hundred million years ago, around the time when South America and Africa rifted apart. Since then, an enormous, tropical rainforest developed in that area, burying the kimberlite pipes and even eroding them.Instead of looking like deep pits, the mines in Brazil look like this. The diamonds from these pipes eroded and washed down stream. The high hardness of diamonds makes them extremely resistant to weathering, keeping them in tact as water carries them down stream. The diamonds then wind up deposited in river sediments, where the mines find them today.Some of the black “carbonado” diamonds we covered in this post are found in mines like this:http://tmblr.co/Zyv2Js1bBbuRy.-JBBImage credit: GIAhttp://www.gia.edu/gia-news-research-Diamond-Mining-in-minas-gerais-brazilRead more:http://www.academia.edu/2758978/The_Carolina_kimberlite_Brazil_Insights_into_an_unconventional_diamond_deposit -- source link

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