Noun
A mineral occurring usually in three-sided or six-sided prisms terminated by rhombohedral or scalenohedral planes. Black tourmaline (schorl) is the most common variety, but there are also other varieties, as the blue (indicolite), red (rubellite), also green, brown, and white. The red and green varieties when transparent are valued as jewels.
Source: Webster's dictionaryA handheld neodymium magnet can be used to identify or separate some types of tourmaline gems from others. Source: Internet
A revised nomenclature for the tourmaline group was published in 2011. citation Erratum: American Mineralogist (2013), Volume 98, page 524. Frank C. Hawthorne and Dona M. Dirlam. Source: Internet
At the time it was not realised that schorl and tourmaline were the same mineral (it was only about 1703 that it was discovered that some colored gems weren't zircons ). Source: Internet
A clarity-enhanced tourmaline (especially paraiba) is worth much less than a non-treated gem. Source: Internet
Castro’s Infinity Locks come in gold, silver and platinum, with a variety of gems, including mint green tourmaline, green garnet and several colors of diamonds. Source: Internet
Any blue tourmaline that is diamagnetic can be identified as paraiba tourmaline colored by copper in contrast to magnetic blue tourmaline colored by iron. Source: Internet