Japan Mine development Co., Ltd.　Mine development(mining and processing gold,other minerals)

　The king of jewels, diamonds. The origin of its name is a Greek word, a (negative) + damazein (takeover), meaning takeover and tough, from the toughest item ever. The mother stone of diamonds is Kimberlite, which is representative of diamonds, where with eclogite, and lamproite, there are 3 types of diamonds.

　Diamonds come out from near the surface of the earth in areas where there are geological transitions, with high pressure and high temperature. Diamonds come out from the earth with the oldest geological stratums, so these are tens of millions of years old.
Concerning the appraisal standards for diamonds, there is a grade called '4C', and the appraisers look at carats (weight), cut (shape), color, quality (scars and murkiness).