Amblygonite

Chemistry: Fluophosphate of aluminum & lithium.
Crystal system: Triclinic; rarely well formed; large & rough; tabular habit.
Color: Transparent; yellow, colorless, gray, pale greenish purple.
Hardness: 6
Cleavage: Perfect: basal; Fracture: brittle, uneven.
Specific gravity: 3.015 – 3.033
Refractive index: 1.611-1.637; Biaxial positive; 0.026
Luster: Greasy to vitreous
Occurrence: In granite pegmatites. Brazil (Minas Gerais), USA (California), Namibia (purple), France, Sri Lanka, Australia (Northern Territory).

Notes
Looks like brazilianite, scapolite, pearly luster on cleavages; LW=weak greenish glow; faceted for collectors.