 | Tourmaline is a crystal boron silicate mineral compounded with elements such as aluminium, iron, magnesium, sodium, lithium, or potassium. Tourmaline is classified as a semi-precious stone and comes in a wide variety of colours. Almost every colour of tourmaline can be found in Brazil, especially in the Brazilian states of Minas Gerais and Bahia. In 1989, miners discovered a unique and brightly colored variety of tourmaline in the state of Paraíba. |  |
 | The new type of tourmaline, known as paraiba tourmaline, came in blue and green. Brazilian paraiba tourmaline usually contains abundant inclusions. It was found the element copper was important in the coloration of the stone. These cupriferous tourmalines are small, rare and precious. Their turquoise to green colours are not duplicated in any other gemstone in the world. |  |
 | Another highly valuable variety is chrome tourmaline, a rare type of dravite tourmaline from Tanzania. Chrome tourmaline is a rich green colour due to the presence of chromium atoms in the crystal; chromium also produces the green colour of emeralds. |  |
