FMF - Friends of Minerals Forum, discussion and message board

[chris]

MinéraLyon, the Lyon's Mineral Show will take place on November 7-9 in Lyon. This year, there will be a special exhibit of minerals from the Oisans, France and from La Mure coal mine which produced beautiful specimens of sphalerite, bournonite, tetrahedrite, ...

More info about the show at : https://www.mineralyon.fr/Index.html

I will try to write a report if I have time to attend the show.

Chris

[chris]

The Lyon's show took place this week-end. As usual, I didn't have time to take photos of the show itself (I'm too talkative for that), but I had the opportunity to take photos of the exhibits. This year it was Oisans & La Mure (which is a nearby mineral locality). Please note some photos have been digitally enhanced to correct my poor photographic skills. However these enhancements only match what the visitor would have seen if he had had the opportunity to visit the show.

The Oisans is a region located in the French Alps. It consists of 6 valleys corresponding to the drainage basin of the Romanche river and of its tributaries : Eau d'Olle, Lignare, Sarenne, Vénéon and Ferrand.

It covers parts of several massifs : Belledonne, Taillefer, Grandes Rousses, Arves and Ecrins. The Ecrins' part being a National Park, crystal hunters focus on the other massifs.

Gardette : gold mine operated from 1781. Even if it never produced much gold, it produced high quality quartz crystals with a metallic brightness to due growth streaks reflecting light at an unusual angle. Many exhibit the famous Dauphiné habit. These crystals sometimes have a 84°33 law referred as « La Gardette » and described by Weiss in 1829. More rarely, smoky quartz is found in association with the uranium bearing brannerite. Besides Quartz, the mine produced chalcopyrite, brannerite, ankerite, siderite, gold...

Challanches : operated from 1767 until the end of the 18th century. 10 tons of silver was extracted during that period, making the mine a rather small one compared with other silver mines. The antimony oxide Allemonite was identified for the first time in 1783. Even if most specimens of the 30 species recorded at the mines were not collectible grade, the area was so rich geologically speaking that the French School of Mines discussed the idea of opening an branch near the mine when it was operating.

Other worthy localities are Cornillon for epidote, Armentier and La Rampe des Commères for the axinite, La Combe de La Selle for prehnite...

[chris]

A couple of specimens for the Challanches. When possible the label is added to give the approximate size of the specimen...

[chris]

On the other side the the Romanche's valley, Cornillon produced mostly epidote, quartz, axinite.

[chris]

On the way from Grenoble to Bourg d'Oisans, the visitor leaves the Lignare's Valley on his right. Near the Ornon's pass, some quartz was found.

[chris]

Just above Bourg d'Oisans in the municipality of Villard Notre Dame lays the most famous (gold) quartz mine of the French Alps: La Gardette. It produced impressive quartz specimens, and some other minerals as well.

[chris]

As I said earlier, La Gardette not only produced Quartz, but other mineral species as well such as:

[chris]

The Grandes Rousses massif hosts the Alpes d'Huez ski resort. Famous for the Tour de France steep run, the massif also hosts several mineral spots. Amongst them Le Rocher de l'Armentier, La Balme d'Auris. These spots produced awesome axinite. Other minerals to note: Baryte, quartz, hematite, ...

[chris]

Facing La Balme d'Auris on the other side of the Romanche's valley, the nearby Rampe des Commères. It produced the same mineralogy as its counterpart on the other side. Higher quartz with chlorite phantoms is found around the Deux-Alpes Ski resort.

[chris]

Higher in the Romanche Valley towards Briançon, just above the Chambon's Dam, you enter the Ferrand's Valley. In this sedimentary part of the area you can find scepter quartz. When going back to the Romanche Valley the Briançon's road reaches an old mine : le Grand Clot.

[chris]

We leave the Romanche Valley and move west to another valley: the Vénéon Valley whose name comes from the stream flowing between it's steep slopes. Just above Bourg d'Arud, and at the entrance of the Ecrins National Park, stands a famous mineralogical spot : Le Plan du Lac.

[chris]

Up ahead, just above Saint Christophe en Oisans, lays the La Selle's Valley. It produced impressive prehnite. Crystal hunting is no longer possible in this valley.

[Michael Shaw]

Thanks for the wonderful report Chris. The countryside there is gorgeous.
Michael

[Don Lum]

Great report, Chris. I am enjoying it very much.

Don

[Mike Wood]

I agree with Michael - looks like a beautiful area to explore, and excellent mineral specimens. Thanks for taking the time to report on the show Christophe, it is much appreciated!
Mike :-)