Japanese mines produced amazing minerals in the 1800s in particular, although now they are hard to find and see, outside of Japanese museums. Here, several, well-formed dark brown to orange-brown Sphalerite crystals are accompanied by a cluster of bright Chalcopyrite crystals from the Oppu Mine in Japan, the same locality that produces the beautiful botryoidal Rhodochrosite. The Sphalerite crystals are translucent and have a resinous luster with crystals up to 3 cm in size. One crystal shows distinct twinning with lines of the contact twin planes very apparent producing a chevron geometry. The largest crystal on the piece shows triangular growth structures on the prominent face. The Sphalerites are intergrown with a group of several, sharply formed, brassy, yellow-green, metallic Chalcopyrite crystals to 2 cm that show light striations. There are also two, metallic gray, 1 cm and 2 cm Galena crystals at the bottom of the piece along with with minor Calcite and Quartz. This is from the Gene Meieran collection - the OLD version of the collection, back when he still had over 5000 specimens including a large small cabinet suite of sulfides such as pyrite, sphalerite, etc. all in drawers (note he had already reduced the collection size from 16,000 or some crazy number at its peak). I got it from Gene probably around 2000-2002 when he sold many other suites to focus on native elements and gem crystals, and sold it at the time to another collector, and got it back relatively recently in yet another collection purchase. I immediately recognized my old friend! Gene told me that he got this, and other Japanese minerals in that old incarnation of his collection, while traveling in Japan in the 1970s and 1980s as he helped develop the factories overseas that built the first microchips at scale.