Sphene natural yellowish green with rainbow spark.
Sphene (titanite) - the remarkable beauty of the stone. If it was a little harder, you would definitely take pride of place among the most popular jewelry stones, such as peridot or demantoid . Its dispersion (the quality that determines the game "the world") is extremely high. This parameter sphene surpasses even diamond.
The name "sphene" in the Greek means "wedge", and indeed, the crystals of this mineral have a characteristic wedge shape. Sometimes this stone is called titanite from the chemical element of titanium, included in the structure of the mineral.
The composition of this stone is a silicate of titanium and calcium. To cut, use large, transparent crystals of a yellow, greenish-yellow or brownish color. Color determine rare earth elements. For example, the most popular yellowish-green variety of titanite owe their color to impurities of chromium.