What is a “unicorn” wine?

Hello there! I'm Dr. Vinifera, but you can call me Vinny. Ask me your toughest wine questions, from the fine points of etiquette to the science of winemaking. And don't worry, I'm no wine snob—you can also ask me those "dumb questions" you're too embarrased to ask your wine geek friends! I hope you find my answers educational, empowering and even amusing. And don't forget to check out my most asked questions and my full archives for all my Q&A classics.
Dear Dr. Vinny,
What is a “unicorn” wine?
—Andy, Cleveland
Dear Andy,
Like the mythical creatures they're named after, unicorn wines are rare and hard to find. They're a little different than “blue-chip” wines, like first-growth Bordeauxs or “cult” California Cabernets, which are not that hard to get your hands on if you have the money. Unicorn wines are special not because of their price, but because their production volumes are so tiny. It also helps if the wine is from a relatively unknown (but currently trending) wine region or producer, and extra bonus unicorn points if the winemaker is deceased, making its rarity even more precious.
Unicorn wines are big among the sommelier set, because the sommeliers get to show off their hip rare wines and access to the seemingly unobtainable. Makes sense to me—it’s not in the interest of a sommelier to serve you a wine that you can buy at the grocery store or any wine shop—especially with a restaurant’s typical markup, so I can understand why they would be pretty excited about posting photos of unicorn wines all over Twitter and Instagram.
—Dr. Vinny