A polytype of
BerboriteBerborite-1T crystals from the Saga I and II Quarries, Mørje, Porsgrunn, Telemark, Norway, is similar to the type berborite from Lupikko Mine, Pitkärenta, Karelia republic, Russia. Guiseppetti et al. (1990) has showned that the actual space group for berborite-1T from the Saga Quarries is P3 and thus belongs to the trigonal-pyramidal class 3.
