3 ensp 0183 ensp According to Bhutan trade statistics limestone is exported under two HS classification 2521 00 10 which is limestone flux and 2521 00 90 which is the limestone and other calcareous stones In 2014 Bhutan exported lime stone flux worth Nu 23 25M US 496 153 to Bangladesh and in 2015 the value stood at Nu 25 95M US 399 230