Duarte & Bastos sells Tourmalines that are rough and cut, calibrated or in free size, polished in great varieties of shapes and in several sizes. Our gem inventory includes a wide range of colors from green to blue indicolite, including the bluish green, blue and greenish blue.
    Among all the well-known precious stones, the Tourmaline possesses the greatest variety of colors, such as yellow, pink, red, blue, and also the rare colorless. Each one of these kinds receives a particular name, like Achroite (colorless), Verdelite (green), Indicolite (blue), etc.
    The larger specimens are cut into a rectangular shape, stepped facets, pear shape (teardrop), oval or in mixed formats, and smaller ones are also found in round forms.
    The color and its smaller degree of transparency are very singular, and these traits differentiate it from other stones. In the case of similar colors to other stones, the distinction can be made by characteristics like pleochroism, birefringence, refraction density, and rate. You may obtain a slight change in color by heating the stone, which turns green into emerald green.
    The Tourmaline is not imitated nor produced synthetically, and stones of average to intense colors command relatively high prices on the market.

Characteristics:

    If you wish to receive further information on the production of Tourmalines at Duarte & Bastos, send us an e-mail or get in touch with our staff in Brazil.

Mohs' Hardness: 7 - 7.5
Relative Density: 3.02 - 3.26
Refraction Rate: 1.616 - 1.652