Avoiding an hangover the mineralogical way

The name Amethyst for the violet variety of quartz derives from the Greek "amethystos" translating in "the non-intoxicated", as it was believed that the mineral protected its owner from drunkenness. 

There are two explanation for the origin of the name and the supposed medical propriety. According to naturalist Pliny the Elder (23-79 A.D., killed by the erution of Mount Vesuvius) the gemstone resembles the color of diluted wine – and so is no longer intoxicating. Or amethyst cups could have been used to serve water as wine during Roman festivities, even if drinking all night long, there was no danger of hangover the next morning.