Leucite, like other feldspathoids, is found in silica poor rocks containing other silica poor minerals and no quartz . At one time leucite was used as a source of potassium and aluminum. Probably due to the high aluminum to silicon ratio, its structure is easily destroyed by acids and this frees the aluminum ions. Leucite, already a pseudomorph from a high temperature phase, commonly is altered to pseudoleucite. Pseudoleucite is not a mineral but a mixture of nepheline , orthoclase and analcime.
Color is clear, white or gray, with yellowish and reddish tints possible.
Luster is vitreous or greasy to dull. Also granular and massive. Cleavage is absent. Fracture is conchoidal Hardness is 5.5 - 6. Streak is white.