1986 Volume 13 Issue 2 Pages 65-74
The first Korean ikunolite is found in Zn–Pb–Ag skarn ores from Wolam deposit of the Yeonhwa 1 mine, Republic of Korea. The average of ten microprobe analyses on nine discrete grains is: Bi 84.48, Pb 4.87, Ag 0.09, S 10.30, Se 0.01, Te 0.13, Total 99.88 wt.%, yielding the empirical formula (Bi3.76Pb0.22Ag0.01)Σ3.99(S2.99Se0.00Te0.01) Σ3.00 (basis: S + Te + Se = 3.00). The identification is substantiated by X-ray micro-diffraction and ore microscopic studies including the reflectance measurement and etch test using 20% FeCl3 solution.
Informations due to the present finding are: 1) the first occurrence in skarn ores, 2) non-essential nature of Se and possibly Te, and 3) direct co-existence with galeno-bismutite (PbBi2S4), bismuthinite (Bi2S3) and native bismuth (Bi) to encompass the composition of the present ikunolite in the ternary system Pb–Bi–S, suggesting the necessity of such off-system component as Ag for the observed association.