The top stories for May. Don’t miss a headline! Sign up for our daily ­newsletter at jckonline.com/newsletters/subscribe.1. Mystery Diamond Color Treatment Stumps GIAAs many as 500 diamonds were exposed to a treatment that ­temporarily improves color up to three grades, reported the GIA.2. Why the Industry’s in a FunkAmong Rob Bates’ hypotheses: a soft worldwide market, falling metal prices, and, of course, millennials.3. The Scott Kay StoryThe past tumultuous year at the brand saw big hires, big ­layoffs, a sale, and the death of its beloved founder.  4. 5 Things You (Probably) Don’t Know About TurquoiseJCK editor-in-chief Victoria Gomelsky shared ­surprising facts about the ­treasured (and timely) gemstone.5. Etsy’s Counterfeit ProblemAnalysts from Wedbush Securities claimed about 5 percent of the site’s items could be counterfeit or constitute trademark/copyright