ad·u·lar·i·a 
(ăj′ə-lârē-ə, -lăr-)
(ăj′ə-lârē-ə, -lăr-)n.
A colorless to milky white mineral of the potassium feldspar group that forms from relatively low-temperature magmas and lacks structural homogeneity.
[Italian, from French adulaire, after Adula, a mountain group of southeast Switzerland.]