Well terminated 2cm Columbite crystal that displays dramatically atop another partial Columbite crystal. Ex. Erich Laskowski collection.

Brassy, metallic Chalcopyrite crystals on translucent Siderite crystals from a limited find at the Kaiwu Mine in China. These were a one time find back in 2012 or 2013 and make stunning specimens due to the contrast in color and form between the Chalcopyrite and Siderite. The Chalcopyrite is bright and metallic with a slightly reddish irridescent surface coloration. The Siderite are translucent brown and lenticular in habit. There are also small white Dolomite crystals in areas. Fifteen cm! This is a large, museum sized specimen, which was unusual for the find, that is amazingly free of any damage (most were smaller and had some damage). This association hasn't been found since.