"Mont Saint-Hilaire hosts a quarry on its Eastern half known as the East Hill Suite. This quarry became one when the wall separating the Poudrette and the Demix quarries was brought down. They have some common and very dissimilar geological environments".*
"For instance, hornfels and sodalite xenoliths are virtually absent from the Demix quarry, and marble xenoliths are uncommon. Hornfels is prevalent on the Poudrette side as well as marble and sodalite xenoliths. It is, therefore, essential to be able to recognize the different environments for the purpose of mineral identification. The following links will display tables of the different rock environments with their associated mineral species".*
* From Mineralogical Record Vol 21, Horváth L. and Gault R.A.