Known for their neon radiating teal color these stones have now become increasingly difficult to find in nice large sizes. This 3.77 carat tourmaline is certified by the Gemological Institute of Thailand (G.I.T.) as containing both manganese and copper and as such is authentic Paraiba tourmaline. The stone features an oval brilliant cut, measures 10.04 X 8.92 X 6.44 mm and displays gorgeous vibrant teal color that has both blue and green hues with blue being just the slightly stronger color (please note that the yellow or white patches are due to the camera's flash). Excellent clarity (dealer rated VS1) places this large sized Paraiba amongst the elite. The tourmaline is prong set and surrounded by beautiful scroll gold work and four round bezel set diamonds that are SI1 clarity and H color. The diamonds total 0.06 carats total weight and the pendant weighs 3.0 grams of 14K white gold. The bail has a nice opening that should accommodate most chains. This magnificent piece is offered by Jill Underhill of Color Symphony (http://www.colorsymphony.com) and will be shipped directly from their location in New Hampshire.
This gemstone (or gemstone that is part of this piece of gemstone jewelry) has been enhanced by traditional heat treatment. Traditional heat treatment is used to improve a stones color, remove color zoning/banding, and improve clarity. This treatment is considered permanent. The only way to tell if a colored stone has been treated is for the stone to be analyzed by a lab. Generally only gemstone laboratories have the equipment necessary to make a qualified judgement with any certainty.
Untreated gemstones are rare and should be verified by a lab independent of the seller. A good rule of thumb is to always assume a gemstone has been enhanced, unless valid certification from a reputable laboratory is available. No one that sells jewelry or gems should be doing appraisals, certifications, or analysis. It should always be an independent third party with no vested interest in the sale.