Tourmaline

 Tourmalines wholesale to the trade today for approx. $10 for a 1 cwt stone of very low grade quality to approx. $400 a one carat example of extra fine quality green. Blue green would be approx. $500 for very fine, 1cwt)  . The price goes up to $1,000 or more per cwt. for extra fine larger examples. The retail price can be several times that, depending on the retailers markup.  

Tourmaline is the gem stone for October. 7 to 7.5 on the mohs scale. Tourmaline comes in many colors, with traces of aluminium, iron, magnesium, sodium, lithium, or potassium providing various shades. It is said to release stress and increase mental alertness.