Blue-Grey Fluorite with Iron Staining | Wheal Mary Ann, Cornwall

A distinctive natural fluorite specimen from Wheal Mary Ann, Menheniot, Cornwall, displaying a beautiful combination of smoky blue-grey, slate-blue and pale greenish-grey crystalline formations. Its angular structure is highlighted by contrasting creamy-white mineral areas and warm golden-brown to rusty-orange staining, creating an attractive example of Cornwall's historic mineral heritage.

Weighing 90g, this compact specimen features a naturally irregular, block-like formation with darker blue-grey fluorite concentrated across several prominent surfaces. Translucent crystal sections, intersecting cleavage planes and earthy mineral coatings give the piece a wonderfully rugged appearance, making it particularly appealing to collectors of British fluorite and historic Cornish minerals.

Specimen Description

This specimen displays a compact, naturally angular formation with an uneven upper edge, broad crystalline faces and a slightly tapered lower section.

Its most striking characteristic is the combination of deep slate-blue, smoky blue-grey and muted greenish-grey fluorite, contrasted by pale translucent mineral sections and extensive golden-brown staining.

Across one prominent face, darker blue-grey crystalline areas appear between lighter fractured sections, creating a patchwork of colour and natural mineral texture.

Several of the darker areas have a subdued glass-like lustre, while neighbouring surfaces appear more matte due to natural coatings and weathering.

The blue-grey colouration varies in intensity, with some sections appearing almost charcoal-grey and others revealing softer greenish-blue tones where light passes through the mineral.

Golden-brown and rusty-orange staining follows natural fractures, crystal boundaries and exposed surfaces, adding warmth and contrast to the cooler fluorite colours.

The staining is particularly noticeable across the upper portion and around several darker crystal sections.

From another angle, the specimen reveals a prominent pale greenish-grey crystalline area surrounded by deeper blue-grey mineral formations.

This lighter section has a more translucent appearance, with angular faces and internal fractures visible beneath the surface.

Smaller interlocking crystals occur around the lower portion, creating a layered structure with a mixture of rough, naturally fractured and smoother crystalline surfaces.

The reverse displays additional dark blue-grey fluorite, interspersed with lighter mineral material and scattered orange-brown staining.

Its upper edge forms an irregular ridge, with several angular crystal faces and naturally fractured sections contributing to the specimen's rugged silhouette.

The side profile reveals a slightly wedge-shaped formation, with darker fluorite concentrated towards the upper and central sections.

Across the surface, subtle changes in transparency create an interesting contrast between the more opaque, weathered areas and the translucent crystal faces.

Some sections display fine natural surface markings, while others reveal internal colour variations and geometric cleavage patterns.

The specimen's angular structure is characteristic of fluorite's crystalline nature, with intersecting surfaces producing a distinctive block-like appearance.

Measuring 54.3mm × 37.7mm and weighing 90g, this specimen is a compact yet visually interesting example of Cornish fluorite.

Its darker blue-grey colouring, naturally weathered surfaces and contrasting iron-coloured staining make it a particularly attractive addition to a British mineral collection.

About Fluorite

Fluorite (CaF₂) is a naturally occurring calcium fluoride mineral belonging to the halide mineral group.

It crystallises in the cubic, or isometric, crystal system and has a Mohs hardness of 4.

Fluorite is widely recognised for its remarkable range of colours, including purple, green, blue, yellow, pink, brown and colourless varieties.

These colours may develop through trace impurities, structural defects and other geological processes occurring during crystal formation.

Blue and blue-grey fluorite can display a variety of tones, ranging from pale icy blue to deeper slate-grey and smoky blue-green shades.

Colour variations within individual specimens may reflect differences in crystal growth, internal structure and geological conditions.

Fluorite commonly forms in hydrothermal mineral veins, where heated mineral-rich fluids circulate through fractures and cavities in surrounding rocks.

As the fluids cool or their chemical composition changes, dissolved minerals may crystallise within these openings.

Fluorite frequently occurs alongside quartz, calcite, baryte, galena, siderite and other minerals associated with hydrothermal ore deposits.

One of fluorite's defining characteristics is its perfect octahedral cleavage, allowing the mineral to separate along specific crystallographic planes.

This property can produce distinctive angular surfaces, triangular cleavage faces and naturally fractured formations.

Although fluorite commonly develops cubic crystals, its cleavage characteristics can create a variety of geometric shapes when specimens are fractured.

Fluorite typically displays a vitreous, or glass-like, lustre, although natural weathering, surface alteration and mineral coatings may produce frosted or matte appearances.

Some fluorite specimens exhibit fluorescence under ultraviolet light, although this varies considerably between individual specimens and localities.

Ultraviolet fluorescence has not been confirmed for this particular specimen.

Wheal Mary Ann & Cornish Mining Heritage

Wheal Mary Ann is a historic mineral locality situated near Menheniot in south-east Cornwall, England.

The Menheniot district forms part of Cornwall's extensive mining landscape and is particularly associated with historic lead and silver mining.

While Cornwall is internationally recognised for its tin and copper deposits, the south-eastern part of the county also contains important lead-bearing mineral veins.

During the nineteenth century, mining operations around Menheniot extracted lead ores, particularly galena, which could also contain economically valuable silver.

The mineral veins of the district formed through hydrothermal geological processes, with heated mineral-rich fluids circulating through fractures in the surrounding rocks.

These fluids deposited a varied assemblage of minerals, including quartz, fluorite, galena, siderite, calcite and other associated species.

Wheal Mary Ann is of particular geological interest because historical geological studies document complex relationships between successive generations of mineral deposition.

The British Geological Survey's geological memoir covering Plymouth and South-East Cornwall records fluorite as an important gangue mineral at Wheal Mary Ann.

Gangue minerals occur alongside economically valuable ores but are not necessarily the principal materials being extracted.

The memoir describes quartz as a significant vein-filling mineral, with chalcedonic material occurring along parts of the vein walls.

Crystalline quartz, galena and siderite are also documented within the mineral sequence.

Historical geological observations indicate that at least two generations of fluorite mineralisation occurred at Wheal Mary Ann.

This suggests that the mineral veins experienced multiple episodes of deposition under changing geological conditions.

Such processes can produce overlapping crystalline formations, variations in colour and complex mineral associations.

Fluorite from historic Cornish localities is particularly appealing to collectors interested in British mineralogy, geological history and the country's mining heritage.

This specimen offers an attractive example of fluorite attributed to Wheal Mary Ann, with its deep blue-grey crystalline sections, natural angular structure and contrasting iron-coloured staining.

Intention & Associated Chakras

Within traditional crystal healing practices, fluorite is associated with mental clarity, concentration, emotional balance and calm.

Blue and blue-grey fluorite varieties are commonly connected with the Throat Chakra, symbolically representing communication, understanding and self-expression.

Fluorite is also associated with the Third Eye Chakra, traditionally linked with intuition, awareness and clear thinking.

Greenish fluorite varieties are sometimes connected with the Heart Chakra, representing emotional harmony and balance.

• Calm: Traditionally associated with peaceful reflection, emotional balance and a settled mindset.
• Mental Clarity: Symbolically connected with clear thinking, understanding and mental organisation.
• Focus: Traditionally linked with concentration, learning and maintaining attention.
• Communication: Blue-toned fluorite is associated with clear expression, understanding and thoughtful communication.
• Intuition: Traditionally connected with awareness, perspective and personal insight.
• Emotional Balance: Associated with harmony, reflection and emotional awareness.

Associated Chakras: Throat Chakra, Third Eye Chakra and Heart Chakra.

Primary Intention: Calm and mental clarity.

These associations reflect traditional spiritual beliefs and are not scientifically established effects of fluorite.

Natural Formation & Symbolism

This specimen retains its natural crystalline structure, angular edges, exposed cleavage surfaces and areas of mineral staining.

Its deep blue-grey and smoky greenish-grey sections create an attractive contrast against lighter translucent crystal formations.

The block-like shape gives the specimen a compact, sculptural appearance, while its naturally fractured surfaces reveal the distinctive geometry of fluorite.

Golden-brown and rusty-orange staining highlights several crystal boundaries and surface features, adding warmth to the darker mineral colours.

The mixture of translucent, opaque and weathered sections provides visual depth, with different crystal faces reflecting light in subtly different ways.

Within traditional crystal symbolism, blue fluorite is associated with communication and clear thinking, while greenish fluorite is linked with emotional balance and harmony.

The combination of these colours is sometimes interpreted as representing a balance between thoughtful expression and emotional understanding.

Beyond its symbolic associations, the specimen's appeal lies in its distinctive colouration, naturally rugged formation and connection to Cornwall's historic mineral-producing landscape.

Specimen Details

• Mineral: Fluorite
• Chemical Formula: CaF₂
• Mineral Group: Halides
• Crystal System: Cubic (Isometric)
• Mohs Hardness: 4
• Supplied Locality Attribution: Wheal Mary Ann
• Location: Menheniot, Cornwall, England
• Weight: 90g
• Dimensions: 54.3mm × 37.7mm
• Formation: Natural fluorite specimen
• Colour: Slate-blue, smoky blue-grey, greenish-grey, cream and rusty-orange
• Features: Dark blue-grey fluorite, translucent crystalline sections, angular cleavage surfaces, natural fractures, mineral coatings and golden-brown staining
• Shape: Raw
• Finish: Natural, unpolished
• Quantity: One individual specimen

You will receive the exact specimen photographed. Natural mineral specimens may display irregular edges, fractures, inclusions, uneven surfaces, mineral staining and delicate crystalline formations.

The acrylic display support, wooden plinth and decorative flowers shown in the photographs are not included.

Sources & References

1. British Geological Survey – Plymouth and South-East Cornwall Area, Geological Memoir (Sheet 348). Geological documentation describing the Menheniot mineral veins, Wheal Mary Ann mineralisation and multiple generations of fluorite formation.
   British Geological Survey Geological Memoir
2. British Geological Survey – Silver, Mineral Resources Consultative Committee Mineral Dossier. Geological and historical information concerning the Menheniot lead-silver mining district.
   British Geological Survey Silver Mineral Dossier
3. Mindat – Wheal Mary Ann, Menheniot, Cornwall. Mineral locality database documenting fluorite and associated mineral species.
   Wheal Mary Ann Mineral Locality
4. University of Cambridge – Fluorite Mineral Collection. Mineralogical information concerning fluorite's chemical composition, crystal system, cleavage and physical properties.
   University of Cambridge Fluorite Collection
5. Henwood, W. J. (1871). Observations on Metalliferous Deposits: On the Lead Mines of Menheniot, Lanreath and Saint Pinnock. Transactions of the Royal Geological Society of Cornwall, Volume 8, pages 699–722.