Rebecca J. Rosen finally answers the age old question, what do Steinways and milk protein have in common? Via The Atlantic:
But ivory wasn't solely prized for its aesthetic value. Ivory's properties — durability, the ease with which it can be carved, and its absence of splintering — uniquely suited it for a variety of uses. Archaeologists and historians have recovered many practical tools made out of ivory: buttons, hairpins, chopsticks, spear tips, bow tips, needles, combs, buckles, handles, billiard balls, and so on. In more modern times we are all familiar with ivory's continued use as piano keys until very recently; Steinway only discontinued its ivory keys in 1982.
More here.