Have you ever seen one of these adorable aberrations pop up in your ice cube tray? They're known as "ice spikes" or "ice-cube stalagmites," although the latter moniker is somewhat misleading since they aren't made by water dripping from above, but rather take place when there is a small crack or hole in the outer layer of ice forming on the cube. As the water expands, it's forced upward through a gradually elongated tube-like structure. Apparently, this is more likely to occur if your freezer is especially cold and if the water has been distilled. I discovered 11 typos in OhioLINK on the search Crytal* and four on Chryst* + Crystal*. Anyway, do try this at home. Ice spikes are very cool.
(Photo from the home collection, circa 2008.)