Fluorescent minerals from Mont Saint-Hilaire, Québec, Canada

Описание: Mont Saint-Hilaire is a low hill in Montérégie, Québec, Canada. It is part of a series of magmatic intrusions, that now occur as low hills called the Monteregian Hills ; those were formed as the North-american plate moved westward over a hotspot (known as the New-England hotspot) in the early Cretaceous.

Magma from the hotspot didn’t reach the surface in most places, including in what is now Mont Saint-Hilaire ; instead, it remained trapped a few kilometers under the surface, where it slowly cooled. Later, the softer sedimentary host rocks eroded, while the much harder igneous rocks better resisted erosion, leaving the less eroded intrusive rocks protuding as low hills, known as monadnocks. The series of intrusives formed over the New-England hotspot is called the Great Meteor Hotspot track.

In most of the Monteregian Hills (Mont-Royal, Mont Saint-Bruno, etc), few minerals occur ; but in Mont Saint-Hilaire, 371 mineral species have been identified, including about 50 species that were unknown to science before being found in MSH. For a long time, this highly unusual mineral diversity, as well as the presence of previously unknown minerals, including some that exist only in MSH, has puzzled scientists. It is now believed that this great mineral diversity is due to enrichment of the magma, when the latter possibly got in contact with a brine pool in the sedimentary rocks during its ascension.

Among the rarities found in MSH, some are highly sought after by collectors, not only for their rarity but in some cases, like carletonite, serandite and rhodochrosite, for their highly aesthetic crystal form and colors. MSH is also home to many interesting fluorescent mineral species, on which this video will focus. All the specimens shown in this video are part of my personnal collection ; this is by no means a complete assortment of all the fluorescent specimens that were found there, but most of the better-known MSH fluorescent species are shown here.

First four pictures of Mont Saint-Hilaire : Wikimedia commons

Tenebrescence explained:

https://www.naturesrainbows.com/post/2016/...

https://www.naturesrainbows.com/post/2016/...

Other useful links:

https://www.mindat.org/loc-599.html

https://www.saint-hilaire.ca/msh.htm

Also, visit the Fluorescent Minerals facebook group for a lot of interesting contents and expert knowledge!