Named after Monsieur Valium, a French explorer, Villiaumite was discovered in 1908 in a collection of rocks from the Islands of Los in French Guinea. Considered as an extremely rare mineral till 1982, Villiaumite has been found more frequently in recent times in sodalite xenoliths (inclusions) in Nepheline Syenite composite rocks.

Nepheline - Syenite, a medium to coarse grained, light to medium gray colored igneous rock is predominantly composed of a silicate mineral called orthoclase (KAlSi3O8). Minerals that are found in Nepheline - Syenite generally occur embedded in massive sodalite or may be in small randomly distributed, irregular shaped cavities not more than 1 cm in dimension.

Xenoliths occur in Nepheline - Syenite which are fine-grained, dense, dark gray to brownish gray and are significantly different from most Nepheline - Syenite found, in terms of their appearance and texture. Sodalite xenoliths have so far produced the largest number of minerals in the growing list of minerals in recent times. Villiaumite is one such mineral found and added to the list.

Villiaumite occurs in colors ranging from pale orange-red to very deep carmine red. With hardness similar to that of an average fingernail that is 2 - 2.5 on the Moh’s Scale and a Specific Gravity of 2.8, Villiaumite is transparent and has a glassy luster.

Composed of approximately 54.75% of Sodium and 45.25% of Fluoride (NaF, Sodium Fluorine), Villiaumite has anhedral to subhedral crystal structure. Commonly associated with Amphiboles, Calcite, Eudialyte, Fluorite, Nepheline, Pectolite and various other minerals from the sodalite xenolith environments, Villiaumite can be easily distinguished from other minerals because of their color and crystal forming habit.