Rubellite: “Ruby” is basically in the name so the two must be related, right? Nope.
Rubellite is actually a Tourmaline. Tourmaline, like Sapphire (corundum), comes in a vast array of colors and even more so than Sapphire with bi-colors and multi-colors but is a completely different mineral. “Tourmaline” actually means “mixed parcel” or “a stone with mixed colors.” Tourmaline is quite hard, just below corundum at 7-7.5 on mohs scale. The trace elements involved in the crystallization process account for the various colors. Aluminium, iron, magnesium, sodium, lithium, or potassium present will affect the color outcome of the final crystal.
The majority of gem quality Tourmaline come from Brazil and several countries in Africa, but at one time California and Maine in the United States were the largest suppliers of Tourmaline. Sri Lanka and Afghanistan also produce gem quality Tourmaline. The world’s largest known cut Tourmaline of 191 carats comes from the Brazilian state of Paraiba.
Tourmaline’s large color variations allow it to mimic many much more expensive gems. In the sixteenth century, the Portuguese even mistook a Brazilian green Tourmaline for an Emerald, but was not discovered until three centuries later. Today, many Tourmaline are falsely sold as other gemstones like Rubies, Sapphires and Emeralds.
Rubellite is a special variety of the Tourmaline species Elbaite. As you may have guessed, Rubellite and Ruby share similar origins of their names meaning “red” or “reddish.” What makes a Rubellite is not only the beautiful red color but a property that few gems have. Most gems’ colors shift depending on the color temperature of the light source, but Rubellite does not; it stays the same rich red in both natural and artificial light. Most pink or red Tourmaline secondary colors shift to a brownish tone under artificial light. They come in variations of purpleish red and red and are notorious for the prevalence of natural inclusions. The manganese that produces the rich red color causes inclusions to be more visible and the more saturated the red, the more inclusions tend to be present.
Tourmaline are known as the most dichoric gems, meaning their crystal structure actually reflects two colors simultaneously. In Rubellite, this is usually red and purple, with red being the main color and purple or pink being the undertone. Of course the more red the higher the value. Because of this dichoric nature and similar color to Ruby, it can be very difficult to distinguish between the two.
Tourmaline, like other gemstones can be treated by irradiation and heat to reduce inclusion visibility, increase color saturation or change colors. Irradiation is quite common and very difficult to detect, thus the treatment generally does not affect the value of the stone. Heat treatment can also be used to enhance the stone. Tourmaline which are strongly included like Rubellite are sometimes enhanced for clarity and this treatment significantly reduces the value of the stone.