In Turkey, there are more than 2/3 of the world's proven reserves of boron. The main deposits of boron located in the western part of the country in the provinces of Eskisehir , Ankara , Bursa and Kutahya . Mining of boron in Turkey is under the control of the state-owned company Eti Mine Works G.M. Since its established in 1935, the company Eti Mine is the largest company in Turkey , engaged in mining and processing mineral resources . The company Eti Mine manufactures and supplies customers a range of enriched minerals and boron refined products such as Colemanite , Ulexite , Tincal ,Borax pentahydrate (Etibor -48),Borax decahydrate , Anhydrous Borax , Boron oxide, Boric Acid.