Today I learned about "Wine Diamonds" They're little crystals of tartaric acid that form in wine - usually white wine.  I've opened a reasonable amount of wine bottles but hadn't encountered them before, but this time ... This is the cork from a bottle of Vidal Blank we got at Henke Winery in Cincinnati.  I picked up the cork just because and noticed it sparkled.  It was almost like someone had glued sand to it. Yes, I broke off a couple of crystals to taste.  I wanted to know if it was sugar or sulfites or something else.  It was slightly sour, so ... acid. These crystals form sometimes when wine is chilled.  They're often mistaken for sediment or impurities, so wineries sometimes batch chill wines before bottling to precipitate them out.  Of course that can change the flavor profile of the wine for the worse.  Apparently Henke Winery doesn't do that, and I'm glad they don't.  The wine tasted great, and the crystals are kind of magical.