Final answer:
Amethyst was highly valued for protection against d.r.u.n.k.e.nness due to an old Greek superstition, reflected in its name "améthystos," meaning "not d.r.u.n.k.e.n," until the late nineteenth century when significant Brazilian and Uruguayan deposits were found, altering its rarity and value.
Step-by-step explanation:
Amethyst, historically, was revered beyond its aesthetic appeal. The ancient Greeks believed wearing amethyst could safeguard against intoxication, giving it the name "améthystos." This belief persisted until extensive deposits were discovered in Brazil and Uruguay in the late 1800s. Prior to this discovery, the gem's deep color was scarce, elevating its worth and reinforcing its association with sobriety. The sudden abundance of amethyst impacted its rarity and diminished its previous symbolic value. Despite this shift, amethyst retains cultural significance for various reasons, including its historical mystique and its continued association with certain virtues like calmness and clarity of mind.