Ametrine Gemstones

The Bicolor Amethyst - Citrine Gemstone

Bicolor Faceted
Ametrine - 8x10 mm - Brazil

Ametrine is the name used when a single crystal of quartz
has zones of gemstone quality amethyst (purple) and gemstone quality
citrine (golden) in contact with one another. The words AMEthyst and
ciTRINE were combined to yield ametrine. Sometimes the name trystine is
used in reference to these purple / golden gemstones.
Cutting Ametrine Gemstones
The artists who cut ametrine plan their cutting to produce gemstones
that display both the purple amethyst and golden citrine. The most
popular cut is a rectangular gemstone that is close to 50% amethyst and
50% citrine. There is often a slight color gradient area between the
amethyst and citrine. Because of this tiny stones of only a few
millimeters are rarely cut. They are not large enough to show both
purple and golden color. It takes a stone of at least several
millimeters in size to show a strong amethyst purple on one side and a
strong golden citrine on the other.
Rough with a sharp transition between purple and golden is the most
desirable.
What Gives Ametrine Its Color?

The colors of natural ametrine are produced by iron impurities within
the quartz. The purple and golden colors are a result of different
oxidation states of iron impurities. Some purple/golden ametrine is
produced in a laboratory by heat treating natural amethyst to alter the
oxidation state of the iron in parts of the rough. Sometimes a color
change is induced by irradiation or irradiation followed by heating.

Synthetic Ametrine
Some synthetic ametrine is produced in a laboratory by growning
"quartz" crystals with zones of various colors. Sometimes a
purple/golden material is produced but synthetic stones in a variety of
color combinations are grown. These bicolor "quartz" stones are
almost always synthetic.
Uses of Ametrine
As a variety of quartz, ametrine is very hard, at seven on the Mohs
Hardness Scale. This hardness along with a lack of cleavage makes
ametrine suitable for almost any jewelry purpose, including rings and
bracelets that might encounter accidental impact. Many consider ametrine
to be an elegant but inexpensive gemstone.

Ametrine Gemstones

Ametrine Gemstones :: تعاليق

Ametrine Gemstones