Kalsilite

Kalsilite (KAlSiO₄) is a vitreous white to grey feldspathoidal mineral that is found in some potassium-rich lavas, such as from Chamengo Crater in Uganda. It has a relative hardness of 5.5.

Kalsilite
General
Category	Tectosilicate minerals, feldspathoid group
Formula	KAlSiO4
IMA symbol	Kls[1]
Crystal system	Hexagonal
Crystal class	6 2 2 – Trapezohedral
Space group	P6322 (no. 182)
Identification
Color	Colorless, white, gray
Tenacity	Brittle
Mohs scale hardness	6
Luster	Vitreous, greasy
Streak	White
Diaphaneity	Transparent, Translucent
Specific gravity	2.59–2.62
References	[2]