To do so, I made rock candy out of Grand Marnier. I made a syrup out of 4 cups of water, 1.5 cups of sugar, and half a cup of Grand Marnier.
Then I suspended in a bamboo skewer in the syrup and waited. And waited and waited and waited. I had to wait about a month to get crystals to form in this amount. And that's a long time for one drink.
It occurred to me later that I'm an idiot, and the alcohol would prevent crystals from forming. Next time, I'll condense the orange liqueur more by simmering it, or dry it out overnight in a food dehydrator so that it's just a sugar.
In any case, it looks cool. After all this effort, I'm a little afraid to actually use it.