This beauty comes from Minas Gerais Brazil and is naturally terminated with rich color.
Tourmaline crystalizes in the form of vertically striated prismatic crystals, sometimes slender and sometimes needle-like. The colour range includes deep pink to red-violet (Rubellite, blue to indigo-blue (Indicolite), yellow (also known as "Peridot of Ceylon" and as Tsilasite), brown (Dravite), green, pink, (Elabaite), orange, purple/lavendar, black (Aphrizite and Schorl), colourless (Achroite), bi-coloured, tri-coloured, multi-coloured, and a variety which exhibits triangular and triskelion formations when sliced perpendicular to the c-axis (Liddicoatite).
The mineral was first reported by J.D. Dana (as Turmalin) in 1837 and is said to be a corruption of the Sinhalese word "turmali" which was applied by Sri Lankan jewelers to describe yellow Zicron, and was subsequently, mistakenly applied to a consignment pf Tourmaline which was sent to Amsterdam; the name stayed and Tourmaline became a group of minerals.
The general composition is reported as: