I WAS ONCE ONE OF THOSE minerals most aptly described as ‘of interest to collectors only,’ but recent scientific research has found uses for me as a ‘fixing agent’ in the production of hydrogen gas for use in fuel cells and secondly as an element in protective clothing. While I was discovered rather late (1896 in Tyrol, Austria), I’m a fairly common calcium aluminum silicate and take my name from my resemblance to a companion in the Epidote series. All pretty heavy stuff, I know. But when not hard at work with serious science nerds, I can be faceted into a very pleasing collector’s gem, appearing in shades from colorless to pale yellow or blush pink — delicate enough for a pendant or ring, if you know where to ask.