(IDEX Online) - A five-carat Paraiba tourmaline - one of the "newest" gemstone varieties - is to be auctioned at Bonhams Hong King with a high estimate of $484,000.Tourmaline was first discovered in the 1500s in a variety of colors. But vivid blue/green examples were only discovered in 1989. They are called Paraiba after state in Brazil where they were found and can command significantly higher prices than diamonds, carat for carat.Highlight of the Jewels and Jadeite sale on June 22 is the modified shield brilliant-cut 5.09-ct Paraiba tourmaline (pictured) set in a platinum ring, accented with 1.91 carats of pear and marquise diamonds. Bonhams describe it as a "quintessential example of the gemstone: rare size, neon color, fine clarity and of Brazilin origin".The most sought-after stones exhibit a vivid neon, almost electric blue, with strong saturation.