Question: What does tourmaline look like?
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In late 1989 a team led by gemstone prospector Heitor Dimas Barbosa uncovered in a small mountain range what some consider to be the finest tourmaline crystals ever found.
A trace of copper gives the tourmalines a vivid turquoise color that had never been seen before in the gems, and is sometimes referred to as "neon".
The "neon" paraiba tourmaline, a vivid blue and blue green, has also been found in other deposits close to the Batalha mine of Barbosa, and also in the neighboring state of Rio Grande do Norte.
The bright colors of this tourmaline are due to the presence of copper.
Around 2000, a similar copper-containing tourmaline was found in Nigeria, although the colors are not as intense.
Around 2005, beautiful crystals of copper-containing tourmaline were found in Mozambique.
Initially, the nomenclature for this tourmaline was "Paraíba tourmaline".
Note the capitalization and the accent on the "i".
In 2006, the LMHC (Laboratory Manual Harmonization Committee) agreed that "paraiba" should refer to a variety of tourmaline, and not indicate a geographic origin.
Note "paraiba" is not capitalized, and does not have an accent on the "i".
For more information on paraiba tourmaline, see article on tourmaline.
The term "paraiba tourmaline" may now refer to gems found in Brazil, Nigeria, and Mozambique that contain copper and have the characteristic blue-green color. 
Some tourmaline gems, especially pink to red colored stones, are altered by heat treatment to improve their color.
Irradiation is almost impossible to detect in tourmalines, and does not, currently, impact the value.
Heat treatment is also used to enhance tourmaline.
Heavily-included tourmalines, such as rubellite and Brazilian paraiba, are sometimes clarity-enhanced.
A clarity-enhanced tourmaline (especially paraiba) is worth much less than a non-treated gem. 
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Some fine gems and specimen material has been produced in the United States, with the first discoveries in 1822, in the state of Maine.
California became a large producer of tourmaline in the early 1900s.
The Maine deposits tend to produce crystals in raspberry pink-red as well as minty greens.
The California deposits are known for bright pinks, as well as bicolors.
During the early 1900s, Maine and California were the world's largest producers of gem tourmalines.
The Empress Dowager Cixi of China loved pink tourmaline and bought large quantities for gemstones and carvings from the then new Himalaya Mine, located in San Diego County, California.
It is not clear when the first tourmaline was found in California.
Native Americans have used pink and green tourmaline as funeral gifts for centuries.
The first documented case was in 1890 when Charles Russel Orcutt found pink tourmaline at what later became the Stewart Mine at Pala, San Diego County.