Johachidolite: Gemstone Information
Johachidolite is CaAlB3O7 and forms transparent pale yellow equant subhedral crystals of the orthorhombic system. The hardness is 7.5 and the SG 3.45. The RI for the alpha, beta and gamma rays is 1.717, 1.720, 1.724, biaxial positive with birefringence 0.007. A strong whitish blue fluorescence is seen under LWUV; under SW a weak blue has been reported. Johachidolite occurs in a nepheline dike cutting limestone in the Johachido district, North Korea. A faceted stone is reported from the Mogok region of Myanmar and the constants and properties described above relate to that specimen.