Serpentine Jade (Bowenite) in Korea

A bowenite deposit, recently discovered in Booyo County, Republic of Korea, is the first of its kind in the country. This deposit is located along the contacts of garnet veins intruding the serpentinite. The bowenite is translucent, dark green in color, greasy in luster, 5 in Mohs ' scale of hardness, ~2.57 in SG, 2.58 in RI, and 1.56 in N_D. The X ray powder diffraction analysis identified the bowenite as antigorite of the serpentine group minerals, whose major chemical compositions are composed of SiO₂ (42.49 %), MgO (39.08 %), Fe₂O₃ (3.85 %), and H₂O (11.87 %) and whose important trace elements include Cr (2 188×10^-6), Ni (1110×10^-6), and Co (58×10^-6). The IR spectrum shows the absorptions at 3 670 (OH stretching), 1 190, 1 070, 980 (SiO stretching) and 610 cm^-1 (OH bending). The DTA/TGA thermogram shows the peaks at 343, 755 and 830.1 ℃. The endothermic reaction at 755 ℃ denotes expulsion of structural water, and the strong exothermal reaction at 830.1 ℃ is related to the formation of olivine. Black inclusions finely dispersed in the mineral are identified, with X ray Gandolfi camera method, as magnetite.