"pure and impenetrable as fine jade"

"The farther out one looked, the darker the color of the water, until it finally became a deep blue-green.  It was as if the innocuous ingredients of the offshore water became more and more condensed by the increasing pressure of the water as it got deeper, its green intensified over and over again to produce an eternal blue-green substance, pure and impenetrable as fine jade, that extended to the horizon.  Though the sea might seem vast and deep, this substance was the very stuff of the ocean.  Something that was crystallized into blue beyond the shallow, frivolous overlapping of the waves -- that was the sea."

-- Yukio Mishima, Spring Snow