These gems are an attractive yellow color and have an index of refraction of 1.61 and 1.64. This is a relatively low index of refraction but is higher than beryl or quartz and on par with topaz and tourmaline . Amblygonite , montebrasite, natramblygonite, natromontebrasite, and a mineral named tavorite all belong to a group of minerals called the Amblygonite Group. Color is generally white or creamy, but can also be colorless or pale yellow, green, blue, beige, gray or pink. Luster is vitreous to greasy and pearly on cleavage surfaces.
Specimens are translucent to less commonly transparent.
Crystal System is triclinic, bar 1. Crystal Habits include short prismatic, tabular or equant crystals referred to as lath-shaped, but more commonly found as anhedral masses and compact grains. Twinning forms elongated, flatten crystals. Lamellar twinning is sometimes seen. Cleavage is in four directions all with varying quality with one direction being perfect, two directions being good and one direction being only distinct.