AMETRINE
 

REFRACTIVE INDEX    1.544  - 1.553
HARDNESS     7
SPECIFIC GRAVITY     2.651

MINERAL  CLASS        Quartz 

 

Sometimes the purple color of amethyst and the  yellow color of citrine are found in the same crystal of quartz. These bicolour  yellow and purple quartz gemstones are called ametrine.  Ametrine comes in three major colors, purple, yellow and orange and usually all three colors are present in one stone.

 

Originally discovered in Brazil, the world's current  supply comes from Bolivia and, therefore this stone is sometimes called Bolivianite.  The crystals from this mine often exhibit an abrupt color transition, which  reflects dramatic changes in temperature during their formation. 

Most of the citrine in the market today is produced by heating amethyst.