▁indices ▁of ▁n α ▁= ▁ 1 . 6 4 4 ▁- ▁ 1 . 6 4 8 , ▁n β ▁= ▁ 1 . 6 5 4 ▁- ▁ 1 . 6 5 7 ▁and ▁n γ ▁= ▁ 1 . 6 6 1 ▁- ▁ 1 . 6 6 8 . ▁ ▁Bo e hm ite ▁occurs ▁in ▁tropical ▁later ites ▁and ▁b aux ites ▁developed ▁on ▁al um ino - sil icate ▁bed rock . ▁It ▁also ▁occurs ▁as ▁a ▁hydro ther mal ▁alter ation ▁product ▁of ▁cor und um ▁and ▁ne ph eline . ▁ ▁It ▁occurs ▁with ▁ka olin ite , ▁g ib b site ▁and ▁di asp ore ▁in ▁b aux ite ▁depos its ; ▁and ▁with ▁ne ph eline , ▁g ib b site , ▁di asp ore , ▁nat rol ite ▁and ▁anal c ime ▁in ▁ne ph eline ▁p eg mat ites . ▁Indust ri ally , ▁it ▁is ▁used ▁as ▁an ▁in exp ensive ▁fl ame ▁ret ard ant ▁add itive ▁for ▁fire - safe ▁polym ers . ▁ ▁It ▁was ▁first ▁described ▁by ▁J . ▁de ▁L app ar ent ▁in ▁ 1 9 2 7 ▁for ▁an ▁occurrence ▁in ▁the ▁b aux ites ▁of ▁Mas ▁Rou ge , ▁Les ▁B aux - de - Pro v ence , ▁France , ▁and ▁named ▁for ▁the ▁Boh em ian - G erman ▁chem ist ▁Johann ▁B ö hm ▁ ▁( 1 8 9 5 – 1 9 5 2 ) ▁who ▁carried ▁out