This is a reply from Rob Celis on 3/26/2020 about the different mining locations used by Ardennes Coticule. I thought this might bring some clarity to some of the information circulating about Regné and Preu.
"The Regné mine closed around 1960-1970 ( i don't know the exact date ) because the owner died. My father bought the mine from that family 20 years ago. We reopened the mining shaft in 2010 but closed it again some years later because the old shaft became dangerous unstable.
That's why you'll see stones mined in Regné on the market.
Before that Thier del Preu was an open mining pit it existed out of +- 25 different small mines. My father bought them all between 1985 and 2010 and transformed it in one big open mining pit ( quarry ).
I have a video that was filmed around 1965 and restored early 2000. It shows the extraction of coticule in the mines of Thier del Preu and the production of stones in the Atelier Burton.
At the end of the video you'll see the old Burton preparing wooden crates full of coticule stones for New York etc...
Also in the last minute you'll see the Atelier Burton from the front. That's our Ardennes-Coticule atelier today, we bought it from the daughter of the old mister Burton long time ago.
Link to video: Coticule 1966_Title_1.mp4 - https://drive.google.com/file/d/1cKbGdlkzMVxrq8Yo3GH7kFIFRQAXzirZ/view?usp=sharing
'Thier' means in local dialect language something like 'hole in ground for rocks'...
'del Preu' is the name of the mountain.
Hence the name 'Thier del Preu'
Link to google maps: Google Maps - https://firstname.lastname@example.org,5.8427217,384m/data=!3m1!1e3?hl=en