The 1878 Hayden Expedition named this pool for its milky, white bottom and gem-like, blue-colored water. Suspended mineral particles in the water also add an opalescent iridescence. Turquoise has no apparent overflow channel, instead water drains through seepage. There is an underground connection with Excelsior Geyser. When Excelsior was active, Turquoise lowered nearly 3 m (10 feet) and took nearly a year to recover.