An odd mother-daughter combination is ruthenium-rhodium 106.
This embraces 98 separate "strategic" materials, including many that have to be imported, going all the way down to ten troy ounces of precious ruthenium metal.
One British paper, for instance, tells about the troublesome chemistry of ruthenium, a rare element that had almost no importance before atomic science was born.
Ruthenium Drops to 8-Year Low as Ipad Demand Hurts Hard-Disk Use Ruthenium slid to an eight-year low on reduced demand for the material used to coat hard disks as consumers favor computer tablets including Apple Inc.’s iPad and smartphones and as manufacturers used metal from inventories.
Sept. 11, 2013 - Bloomberg