The red variety of the mineral tugtupite, a rare silicate closely related to sodalite, has been used as a gemstone since 1965. This article presents the history of the mineral and details of its mineralogy and gemology. A recently discovered light blue variety of tugtupite is also described. Thus far, tugtupite has been found in only two localities: (1) Lovozero, Kola Peninsula, U.S.S.R., where it occurs as very small grains; and (2) Ilimaussaq, South Greenland, where it has been located at several places within the Ilimaussaq intrusion. Gem-quality tugtupite has come almost exclusively from one occurrence, a set of hydrothermal albite veins from the Kvanefjeld plateau in the northwestern corner of the Ilimaussaq intrusion.
