Agrellite

Agrellite
General
Category	Silicate minerals
Chemical formula	NaCa₂FSi₄O₁₀
Identification
Color	White, grayish-white, greenish-white
Crystal habit	Lath - shaped like a small, thin plaster lath, rectangular in shape
Crystal system	Triclinic
Cleavage	perfect [110]
Mohs Scale hardness	5.5
Luster	pearly
Refractive index	nα = 1.567 nβ = 1.579 nγ = 1.581
Optical Properties	biaxial
Birefringence	δ = 0.014
Streak	white
Specific gravity	2.88
Diaphaneity	transluscent
References	^[1]^[2]

Agrellite (NaCa₂FSi₄O₁₀) is a mineral found in Quebec, Canada. It is also known from few other areas.

It is named in honour of Stuart Olof Agrell. [3]

References