Traditionally, blue and green tourmaline has been graded using standards borrowed from ruby, sapphire, and emerald. Darker-toned stones (seventy-five to eighty-five percent) have been the most sought after. 170 However, the hottest Paraiba colors are not sapphire-like or emerald-like dark primary hues, but vivid pastel hues in the blue to green range with tonal values between forty-five and sixty percent. Terms like “neon,”

“Caribbean blue,” and “electric green” aptly describe the gems of Paraiba. Within a year of the discovery, prices of Paraiba stones over a carat escalated from several hundred to several thousands of dollars per carat, prices that would have been unimaginable just a year before. Paraiba produced darker-toned (eighty to eighty-five percent) stones with a seventy-five percent primary hue of blue and a twenty percent secondary hue of green that resembled sapphires from Australia and Thailand. These stones, among the rarest and most sought after tourmaline variety, the so-called sapphire-blue indicolite, were promptly heat treated. Those that turned a lighter-toned neon blue greatly increased in value.

Unfortunately the San José da Batalha mine was mostly exhausted within a few years but not before the tourmalines of Paraiba already had passed into legend.

The effect of this discovery was twofold: first, it focused attention on tourmaline and established a tourmaline aristocracy, giving the gem something it had previously lacked: snob appeal. Secondly, attention was shifted from the ruby-sapphire-emerald look-alike standard to a new appreciation of so-called Paraiba look-alikes. That is, medium-toned stones in the blue to green hues earned a new respect. Finally, tourmaline began to emerge from the shadows and to be appreciated for itself, as an important gemstone beautiful and valuable in its own right.