Karen, rubellite is a pink tourmaline. In "Gemstones of the World"
by Schumann. He says, “According to color, the following varieties
are recognized in the trade: rubellite, pink to red, sometimes with a
violet tint; ruby color is the most valuable.” Every stone in those
colors illustrated is labeled “rubellite”. In my mineralogy book, the
variety of tourmaline that keys out red is called “Rubellite”.
However, it looks to me like one could make a red stone out of the
center of a watermelon tourmaline, and I don’t think that the
chemical formula would be the same as the pink tourmaline called
that is formed in lithium mica, as in the San Diego area deposits,
which are colored by lithium. I am neither a gemologist or a
jeweler. A spectrographic analysis would probably determine whether
or not the stone contains lithium or another coloring agent (iron?)
but I don’t know if such a test is done on finished stones. If the
trade goes by color only, everybody is correct. Sincerely yours, Rose
Alene McArthur