California can boast many superlatives: it contains the lowest point in the continental USA, the tallest, largest and oldest trees in the world, and it is the most populous state in the country. But to my mind, it also deserves the title of Home of the Weirdest Rocks, and it owes that honor to one rock in particular: the tufa. Essentially, it's a common rock -- limestone -- that forms in uncommon circumstances -- underwater. When calcium-rich underwater springs mix with lakewater rich in carbonates, a... READ ON