Semi-Precious Gemstones: Rubellite
Rubellite (Elbaite) used in Jewelry
Source: Afghanistan, Brazil, Madagascar, Mozambique, Nigeria, Russia (Urals), Sri Lanka, USA
Rubellite (Rubylite) is a red, reddish-purple, or pink variety of elbaite which is in the tourmaline group of minerals. The name "rubelite" (rubellit German, rubellita Spanish) is derived from the Latin name rebellus or "reddish," and is one of the oldest varietal names for a color of tourmaline.
Rubellite (elbaite, sodium-lithium tourmaline) is a lithium-rich complex crystalline silicate (cyclosilicate) containing aluminum, boron and trace amounts of magnesium and iron. Rubellite occurs in pegmatites found in both igneous and metamorphic rock.
Rubellite is one of the most common varieties of tourmaline. The principle impurity in elbaite that causes it to be red is manganese in its 'plus 3' valence (Mn+3) state. Both natural, and man made irradiation can enhance the color of this mineral by producing more Mn+3 from preexisting Mn+2 by oxidation, or the production of color centers. The details of this process are still being worked on, and some color enhancement may be of a temporary nature.
Rubellite (Elbaite) Nomenclature
When the name "rubellite" was proposed, the naming of a natural material that can also be a gemstone was more of an art than a science. Chemistry was still in its infancy and schorl, an sodium-iron tourmaline, and the most common species of tourmaline, was not yet grouped with rubellite as part of the "tourmaline group." Other colors of the elbaite, of which rubellite is a variety, waited to be included in the tourmaline group, and perhaps be given their own name.
As the scientific bases for naming naturally-occurring substances/minerals became better it was determined that schorl and elbaite form a continuous solid solution between the idealized compositions of the endmenbers. The name rubellite stayed in used because it is an economical and useful way of describing reddish tourmaline. It is tempting to call this mineral "elbaite" instead of rubellite because it is elbaite that produces most of the gem quality tourmaline, but this would not be correct.
Rubellite bracelet by Michael Zobel |
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Faceted rubellite (photo: Jeffrey R. Smith) |
Science again made progress and found more minerals (species) to be included in the tourmaline group. Three of these species besides elbaite are liddicoatite,
dravite and uvite, all of which have been cut into gemstones that are reddish in color. Just how many reddish tourmalines have been cut from these other three species is hard to say because of the lack of testing. Species of tourmaline can not be determined by color alone, or by normal gemological testing methods.
At some point along the evolution of rubellite as a varietal name for red tourmaline, changes were made to the definition. The color could now include both pinks and reds, as along as the color did not brown out under artificial light. The gems that did become brownish can still be called "red tourmaline" or "pink tourmaline," but may not be called "rubellite." Rubellites can have shades of orange and purple as long as red is the dominant color. In fact, many high-quality rubellites may become purplish under white light that is rich in the blue (cool) end of the spectrum.
Rubellite Characteristics & Occurrence
Rubellite, and other similarly colored tourmalines tend to have more inclusions than other colors of tourmaline. Eye-visible inclusions are normal in rubellite, and loop-clean gems are rare. Generally, the more saturated the color of a rubellite specimen, the more included it is. The prevalence of inclusions does vary with deposits, and Nigeria has produced a large amount of Rubellite of excellent color and saturation that is also flawless.
Rubellite is found in most major tourmaline producing areas. Brazil has probably produced the finest Rubellite and the principal sources are in the federation of Minas Gerais in southeastern Brazil, with the finest varieties coming from the Ouro Fino mine in Coronel, Murta. Other locations of note are Afghanistan and Pakistan, Nigeria, Madagascar, Mozambique, Burma, Russia and the United States.
Rubellite (Elbaite) Crystallography, Chemistry, Physical Properties
Rubellite (Elbaite) Optical Properties
The majority of facet-cut rubellite on the market may have been heat-treated and/or irradiated to improve color. Certain varieties of rubellite can display (pleochroism) causing a slight color shift due to pseudochromatic coloration, usually adding a yellowish-orange hue.
Bibliography and Reference on Rubellite
1. Paul R. Shaffer, Rocks, Gems and Minerals  . Martin's Press
3. Renee Newman, Gemstone Buying Guide . International Jewelry Publications; 2nd edition
3. Antoinette L . Matlins, Antonio C. Bonanno, Gem Identification Made Easy . Gemstone Press
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