FMF - Friends of Minerals Forum, discussion and message board

[colin robinson]

Exploring Skears low level back in the 80s. The top pic shows the level driven through boulder clay where it requires no support. Where it passes through shale it is stone arched but ground pressure frequently causes collapses.

[Jesse Fisher]

Another lesser-known Weardale locality. The Stanhopeburn Mine was worked for fluorspar off and on through much of the 20th century, finally closing around 1985. The mine was not a prolific specimen producer, however. The specimen came with a Gregory, Bottley & Lloyd label which appears to date to the mid 1980s, so it is likely that the specimen dates from the last period of mining.

[colin robinson]

Stanhopeburn is probably better known for the cerussite specimens it produced. Some nice fluorites also came out of the limestone quarries and opencut ironstone workings lower down the burn. This 14cm plate is from the Trough vein on the east side of the burn.

[Jesse Fisher]

Another relatively unknown Weardale location, the Newlandside Quarry. An open cast stone quarry on the Great Limestone, located south of the River Wear near Stanhope. Quarrying has exposed some mineralized veins that occasionally yield fluorite specimens.

[Tobi]

[James Catmur]

Tobi, I think they have been called 'heart twins'?

[colin robinson]

[colin robinson]

Newlandside fluorites are renowned for the amazing colour zoning to be seen in some crystals. This battered old thing has seen better days but it does show the zoning quite well. Interestingly a vein worked in the western quarry produced pink crystals - a very rare colour for Weardale. Sadly the vein was quarried away many years ago.

[colin robinson]

A little anecdote to add here. Messers Greenbank and Sutcliffe, founders of the Rogerley Mine, attempted to work the Quarry Hills vein in Newlandside until the then owner, Tommy Wilson caught them and told them to 'bugger off'. Tommy was an old man when I first met him and he told me that he and his sister used to get fluorite specimens in exchange for cigarettes from the prisoners of war who were billeted nearby and put to work in the quarries during the 1914-18 war.

[James Catmur]

[Jesse Fisher]

I've also seen the occasional "double twin" from the Rogerley Mine. I've never heard these referred to as "heart twins." That is usually applied to calcite twins of the appropriate morphology from West Cumbria.

[James Catmur]

If you look at them from one angle it looks a little like a heart. I am not saying it is a good description but it is used. I.e., from a commercail web site, I quote "An aesthetic English fluorite featuring a large double twinned crystal, 'heart' shaped and measuring 2cm in width."

[Jesse Fisher]

Personally, I think calling them "heart twins" requires more than a little imagination, but then, the history of commerce is full of imaginative descriptions. I recall selling a wholesale lot of fluorite to an enthusiastic Japanese customer a few years back. She had a website, and though mostly in a language I don't know, it was obvious that it was selling to the new-age and metaphysical market. One of the few English bits, however, claimed that Rogerley fluorite was "the stone of genius!" Considering just how much money I lost on that venture, I am dubious of the claim.

But getting back to the theme of this thread, here is a fluorite from another little-known Weardale location. The Carricks Mine is located near the village of Ireshopeburn and was worked for iron ore coming from flats of oxidized iron carbonates. Most of the workings were 19th century, but the mine was reopened for a short period during the early 1940s.

[colin robinson]

Nice one, Jesse. The Grove Heads opencut worked one of the veins cut by Carricks level and produced similar material, though not quite as 'fresh' as the ankerite/siderite was oxidized to goethite pseudomorphs. I have to agree that calling double-twinned fluorites 'hearts' is rather misleading, certainly on a site like this.

[colin robinson]

Apologies for the picture quality but this is a scan of photo of a double penetration twin of fluorite (not heart-shaped) recovered from Heights West Cross Vein in the early 1990s. It is 3cm on the long side.