3 O 8 Composition Sodium aluminum silicate, often with the sodium partially replaced by calcium or potassium. If calcium replaces more than 10 percent of the sodium, the mineral is not Albite, but a different member of the Plagioclase Feldspar group . If potassium replaces more than 10 percent of the sodium, the mineral is not Albite, but Anorthoclase . 8 Color White, colorless, cream, light yellow, light blue, light green, pale red, light brown, gray. Some Albite is iridescent .
Crystals are usually flat and bladed , and often in compact groupings.
Also occurs as tall prismatic and short, stubby , tabular crystals. These crystals are usually in groupings, and rarely occur singly on a matrix . Crystal twins are common. Other forms are grainy , massive , columnar , and rosette . Crystals are sometimes striated .