Shades of AGTAOpals were the biggest trend to come out of the 2015 ­American Gem Trade ­Association’s Spectrum and Cutting Edge awards. ­According to CEO Doug Hucker, there were more opals than anything else in the contest’s 31st year.“And not just Ethiopian opal. There was a lot of black opal,” he says. “I think it’s because designers are getting into combining colors—interesting uses of color. Opal gives you a great opportunity to surround it with stones like paraiba tourmaline and tsavorite garnet that bring out the colors you see in opal.”In total, there were 471 entries, 377 of which appeared in the finished jewelry (or Spectrum) portion of the contest, up from last year’s 460.The bridal category, ­including engagement rings with colored stone centers, also saw a bump in submissions, as did men’s entries. “We used to have a tiny little area with men’s ­j