Abstract
A rare assemblage of tellurides has been found in a vein of the Yokozuru mine, Sannotake skarn zone, North Kyushu. The tellurides are melonite, volynskite, hessite, and petzite whose compositions correspond to Ni0.98 Te2.00, Ag0.99 Bi1.01 Te2.00, Ag1.99 Te1.01 and Ag2.93 Au1.03 Te2.04 respectively. Some grains of hessite contain selenium up to 0.68 wt.% replacing tellurium. Optical properties are described for melonite and volynskite. Values of reflectance and microhardness were obtained upon melonite (VHN=67), volynskite (40–80), and siegenite (467–551).
Paragenetic relation suggests that the mineralization of the vein started with deposition of scheelite and quartz, followed by Cu–Bi–Fe sulfides, and ended with the rare mineral assemblage of Ni–Bi–Au–Ag–Te system.
