Blue John

A variety of Fluorite

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Blue John

Old Tor Mine, Castleton, High Peak, Derbyshire, England, UK

Blue John

Castleton, High Peak, Derbyshire, England, UK

Blue John

Castleton, High Peak, Derbyshire, England, UK

Blue John

Old Tor Mine, Castleton, High Peak, Derbyshire, England, UK

Blue John

Castleton, High Peak, Derbyshire, England, UK

Blue John

Old Tor Mine, Castleton, High Peak, Derbyshire, England, UK

Blue John

Castleton, High Peak, Derbyshire, England, UK

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About Blue JohnHide

Formula:

CaF₂

Name:

The name was given by two miners, John Kirk and Joseph Hall in the 18th century in the same style as the name 'black jack' which was the local name for sphalerite.

First Recorded Locality:

ⓘ Blue John Mine (Blue John Cavern), Castleton, High Peak, Derbyshire, England, UK

A local name for a banded white/purple variety of fluorite from the Castleton area of Derbyshire, England, UK.

Visit gemdat.org for gemological information about Blue John.

Unique IdentifiersHide

Mindat ID:

698 (as Blue John)
1576 (as Fluorite)

Long-form identifier:

mindat:1:1:698:5 (as Blue John)
mindat:1:1:1576:5 (as Fluorite)

Chemistry of Blue JohnHide

Mindat Formula:

CaF₂

Element Weights:

Element	% weight
Ca	51.333 %
F	48.667 %

Calculated from ideal end-member formula.

Elements listed:

Ca, F - search for minerals with similar chemistry

First Recorded Occurrence of Blue JohnHide

First Recorded Locality:

ⓘ Blue John Mine (Blue John Cavern), Castleton, High Peak, Derbyshire, England, UK

Common AssociatesHide

Associations Based on Photo Data:

13 photos of Blue John associated with Fluorite	CaF₂
4 photos of Blue John associated with Baryte	BaSO₄
1 photo of Blue John associated with Galena	PbS

Other InformationHide

Health Risks:

No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.

Internet Links for Blue JohnHide

mindat.org URL:

https://www.mindat.org/min-698.html
Please feel free to link to this page.

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Mineral Dealers:

Buy from D. Joyce minerals

References for Blue JohnHide

Reference List:

Palache, Charles; Berman, Harry; Frondel, Clifford (1951) The System of Mineralogy (7th ed.) Vol. 2 - Halides, Nitrates, Borates, Carbonates, Sulfates, Phosphates, Arsenates, Tungstates, Molybdates, Etc. John Wiley and Sons.

Localities for Blue JohnHide

Showing 5 localities.

This map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the

symbol to view information about a locality. The

symbol next to localities in the list can be used to jump to that position on the map.

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Locality ListHide

- This locality has map coordinates listed.

- This locality has estimated coordinates. ⓘ - Click for references and further information on this occurrence. ? - Indicates mineral may be doubtful at this locality.

- Good crystals or important locality for species.

- World class for species or very significant. (TL) - Type Locality for a valid mineral species. (FRL) - First Recorded Locality for everything else (eg varieties). ~~Struck out~~ - Mineral was erroneously reported from this locality. Faded * - Never found at this locality but inferred to have existed at some point in the past (e.g. from pseudomorphs).

All localities listed without proper references should be considered as questionable.


Norway
Vestland Øygarden Fjell ⓘ Ågotnes (CCB Oljebasen)	Larsen et al. (2021)

UK (FRL)
England Derbyshire High Peak Castleton ⓘ Blue John Mine (Blue John Cavern) (FRL)	Dewey et al. (1922)
ⓘ Old Tor Mine	[www.thamesvalleyminerals.com]
ⓘ Treak Cliff Cavern (Treak Cliff Mine)	Mason (1976) +1 other reference
ⓘ Wall Shaft Mine	Quirk (1986)

Quick NavTop About Blue John Unique Identifiers Chemistry First Recorded Occurrence Common Associates Other Information Internet Links References Localities Locality List

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