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 GIA
As 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 Funk
Among Rob Bates’ hypotheses: a soft worldwide market, falling metal prices, and, of course, millennials.

3. The Scott Kay Story
The 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 Turquoise
JCK editor-in-chief Victoria Gomelsky shared ­surprising facts about the ­treasured (and timely) gemstone.

5. Etsy’s Counterfeit Problem
Analysts from Wedbush Securities claimed about 5 percent of the site’s items could be counterfeit or constitute trademark/copyright infringement.