Gyokuro, whose name means "jade dew" is Japan's finest and often costliest tea. It is not uncommon for a pound of the rarest Gyokuro to sell for thousands of dollars. What makes this variety unique? While the young leaves of the spring flush develop, the tea bushes are shaded from sun for three weeks. The sun-deprived tea that grows in the shade is high in chlorophyll, which makes it darker than normal, but lower in tannins, which makes it sweeter and mild tasting.