1953 Volume 1 Issue 1 Pages 54-62_1
A new mineral from the Hol Kol mine, North Korea of the composition Mg2B2O5, named suanite, has been described. The mineral is found usually as fibrous aggregates associated with kotoite and other borate minerals in marble which borders the gold-and copper-bearing diopside-clinohumite skarn mass. The crystal usually elongated parallel to  is monoclinic with the following dimensions: a=12.10Å., b=3.12Å., c=9.36Å., β=104°20′ (Weissenberg photographs, CuKα ?? =1.54Å.). The space group C52h-P21/a. The unit cell contains 4[Mg2B2O5]. Colourless. Hardness 51/2. Sp. gr. 2.91. Opt. properties: α=1.596, β=1.639, γ=1.670 γ α=0.074, 2V=70° (negative); r ?? v, weak; X ?? b. The chemical analysis by N. Saito and N. Kokubu follows; SiO2 0.60, Al2O3+Fe2O3 0.95, MgO 46.63, CaO 5.06, B2O3 40.08, CO2 5.01, H2O(+) 0.90, H2O(-) 0.23, total 99.46%. After deduction of CaCO3 and other impurities, MgO 53.7, B2O3 46.3% against the theoretical composition MgO 53.66, B2O3 46.34%. The mineral is not easily affected by cold HCl. The X-ray powder diagram of the mineral is very similar to but definitely different from, that of the artificial Mg2B2O5, to which it is converted when heated up to 1, 000°C..