Saturday, February 28, 2015

Paraiba Tourmaline

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 ParaĆ­ba.
The new type of tourmaline, which soon became known as paraiba tourmaline, came in blue and green. Brazilian paraiba tourmaline usually contains abundant inclusions. It was determined that 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.
Paraiba tourmalines are among the most sought-after, and most expensive gemstones in the world. Prices continue to climb.

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.



See : http://pennystockjournal.blogspot.ca/2013/12/rubellite-tourmaline.html
See ----->http://pennystockjournal.blogspot.ca/2013/11/gemstones-of-minas-gerais-brazil.html