The Bull Vein is an east-west vein that bisects the old quarry bench and there are some remnant mineralised flats that have not been quarried away by the old Cement works. The vein is named for Fred Bull, a local collector, who collected some lovely yellow crystals there back in the late 1990’s.

The pockets are generally small and collapsed, but the sheer variety of colours and associations with the Fluorite in the vein is truly outstanding.

The Fluorite crystals form as single equant and elongated cubic crystals; interpenetrant twins to 2 cm and composite crystals up to 6 cm. They are often gemmy and vary in colour between acidic lemon-yellow, ginger-lemon, ginger-honey and golden-lemon. Zoning is common and varied and may contain delicate bands of lilac, lemon-yellow or sky-blue.

Some crystals display at least five distinct colour bands including lemon, colourless, blueish-grey, marine-green and nested yellow phantoms. Associated minerals include snowy-white Calcite and micro-crystallised Quartz.

The Fairy Holes Pocket is named for a natural cave system into which the former Eastgate-Blue Circle quarry impinged and partly consumed.

Interpenetrant twinned Fluorite crystals coat an iron-rich altered limestone matrix containing Galena, with the twins ranging up to over 2 cm on their longest edges.

The Fluorite tends to be leafy-emerald green, with many crystals displaying mild to excellent colour-zoning in shades of green and purple, some with bright emerald-green edges and a mild lilac interior.

Crystals are of the elongated cubic habit, with smooth faces and distinct nested square growth patterns. They often contrast against a layer of snow-white Calcite.

In direct daylight the Fluorite naturally fluoresces delicate lilac while the inner purple banded zone is bright Royal-purple.

Harvest Pocket forms yet another small cavity section within The Bull Vein and is named for the autumnal colours found within its cavity.

Translucent straw-yellow and lemon cubic Fluorite crystals occur on an iron-rich, altered limestone matrix, with crystals ranging from 1.5 to 3 cm. Larger crystals are gemmy whereas smaller cubes become cloudy and opaque. Many crystals exhibit intricate colour bands which alternate between yellow and lavender; with 16 bands visible in some crystals.

Overgrowths of drusy cream Calcite are common and occasional up-turned sprays of opaque, off-cream Calcite crystals form an array of splayed crystals to 8 cm.

Helen’s Pocket is just one small zone within the extended Wilson Vein, the latter only determined during October 2020.

High quality, interpenetrant twinned Fluorite crystals of an understated leaf-green cover an ironstone matrix. Crystals tend to be ice-clear and are extremely gemmy with a bright lustre. The largest twins measure to over 2 cm, the crystal faces are mirror-flat with most displaying fine, concentric rectangular growth patterns. In sunlight the crystals fluoresce royal purple at differing intensities, the largest twins reacting most.

This pocket was named after Helen Wilkinson who collected lovely specimens there in the late 1990’s.

Layer Cake Pocket was a very small cavity within the yellow Fluorite zone of The Bull Vein and is characterised by its pervasive association with Galena.

The Fluorite tends to be more amber-yellow than lemon and can form excellent flattened cubes, tending to almost tabular, of up to 2.5 cm.

These crystals can be ice-clear, exhibiting remarkable gemminess and superb colour-zonation with a broad outer colourless zone followed by delicately-thin lilac lines and narrow bands.

The contrasting Galena forms heavily etched and pitted lead-grey cubic crystals to 2 cm with a flat, matt metallic lustre, over which are scattered tiny colourless to milky Quartz crystals.

The Lemon Meringue Pocket sits within the yellow Fluorite zone of The Bull Vein and is characterised by the delightful combination of citrus lemon-yellow cubic Fluorite crystals generously sprinkled with milky-white Quartz crystals.

The Fluorite develops cubes of up to about 2 cm and these tend to be transparent and gemmy, covering a pale apricot altered limestone matrix.

The Fluorite tends to have outer colour-zoning close to the crystal’s surface, with an outer rim of near colourless Fluorite changing to alternating pencil-thin teal blue and pale grey bands, all containing the central and dominant lemon cube.

The Minty Cheesecake Pocket was another very small cavity within the Poison Ivy Pocket.

This form of Fluorite crystal, although specimens were few, warranted a new name because of their distinguishing intensity of aerated minty-cream-green faces framed by gemmy pastel-green corners and edges. The latter turn more emerald-green in daylight.

Both the colour and texture of the faces are a dead-ringer for the popular cheesecake made from a famous brand of bubble-filled peppermint chocolate!

The minty-cream cheese faces are uniform, light peppermint green and have a granular, sucrosic texture and lustre

The Poison Ivy Pocket is within The Bull Vein complex and runs as a series of lenticular sub pockets along the eastern flank of the vein. It is characterised by complexly colour-zoned green Fluorite crystals, ranging between 2 and 3.5 cm on edge.

Often the green Fluorite crystals form a domed intergrown cluster which covers greyish-white Fluorite overlying an iron-rich altered limestone matrix. The cubic crystals have acidic apple-green gemmy edges and corners grading to translucent frosted face centres of sugary whiteish apple green.

The contrast between the cloudy centres and gemmy corners and edges is remarkable and delightful. In direct daylight the greens intensify and the gemmy frameworks glow mild to bright blueish-purple due to natural daylight fluorescence.

Back-lit, the cubic crystals are frequently framed by bright lime-emerald green, perfectly parallel and gemmy edges.

The Sherry Twins Pocket is within The Bull Vein complex and produced a limited suite of sherry coloured, often large, interpenetrant cubic twinned Fluorite crystals which typically grade from transparent with many gemmy zones through to a base of clouded white Fluorite, often all within the same crystal.

Twins can attain 4.8 cm and occur in various hues of sherry brown, including amber, light caramel, clove, plum, warm honey and lemon-honey yellow. Crystals can be extremely gemmy, typically with sharp edges, mirror-smooth faces and a waxy yet glassy lustre.

Excellent zoning may contain concentric bands of lemon, lilac, colourless, honey, sea-green, cucumber-green and lavender.

In sunlight the sherry tones turn to daylight fluorescent warm purples and reddish-violet. Rarely, dark chocolate-brown etched Siderite crystals are associated.

The Toxic Apple Pocket was a small cavity sub-set within the main Poison Ivy Pocket, itself part of The Bull Vein complex, that only produced a handful of specimens. The Fluorite is like that of Poison Ivy, but is much more an acidic green, reminiscent of sour gooseberries or tart baking apples.

The Fluorite forms as single, inter grown cubic crystals to around 3 cm, with characteristic transparent gemmy corners and edges which grade to faces swirled with cotton wool-like cloudy inclusions of light peppermint-green Fluorite.

In direct daylight these Fluorites do not fluoresce, but their colours intensify to richer greens. Under LWUV they are strongly fluorescent lavender-white and mid-lilac.

The Sugar Plum Pocket was a relatively small cavity in The Bull Vein and so produced a very limited suite of specimens.

The Fluorite tends to be developed as domed mounds of champaign to sherry yellow crystals of between 1 and almost 3 cm on edge and often as elongated cubes.

In daylight their outer faces fluoresce a delicate yet distinctive plum purple, all of which are heavily dusted with sugary micro-crystals of gemmy colourless Quartz, hence the name. sThe colour contrast between the Fluorite and Quartz is distinctive and arresting.

Named for Jakub Sauermann of the UKMV specimen recovery team, who discovered this football-sized pocket in The Bull Vein in September 2021.

It contained exquisite rich yellow Fluorite crystals, some colour-zoned, alternating between golden-amber and lemon-yellow, edged delicate pale sky blue.

Some display a more equal balance of blue and lemon where blues may morph towards leaf green and intensify further with daylight fluorescence.

Crystals range from transparent with cloudy centres to gemmy with perfect optical clarity, with cubes from 1 cm to 5 x 5 x 3 cm elongated prisms.

Fluorite from the Hailstorm Pocket is identical to that of Purple Rain, the only difference being the Galena crystals have a pervasive coating of cream to pure white Hydrocerussite. On excavating the three-metre-long Purple Rain-Hailstorm flat, many of the Galena crystals were coated with a film of white Hydrocerussite, a basic lead carbonate (Pb3(CO3)2(OH)2), reminiscent of golf ball-sized hailstones and even larger!

Although occurring amongst the Purple Rain Fluorite with Galena, such specimens are named Hailstorm pocket to distinguish them from the uncoated, bright silver Galena. Interpenetrant twins of Purple Rain and Hailstorm Fluorite equally fluoresce intense blackberry purple in direct daylight. Single cubic crystals do also fluoresce, but not as intensely as the twins, a phenomenon commonly observed in this part of Weardale. Occasionally, fluid inclusions are also present.

Less than one month into the 2021 season, miners encountered a large clay-filled pocket in Pit 1, associated with the Fairy Hole Vein, containing excellent specimens of purple-blue Fluorite and Galena.

Named the Purple Rain Pocket, it comprised of a complex series of connected Fluorite-filled cavities where the distinction between vein and flat was often ill-defined.

Many of the Fluorites are associated with superb bright silver galena crystals. The Fluorite is characteristically translucent deep inky purple with permutations of blue and mauve.

It forms as interpenetrant twins and fine single cubic crystals, sometimes with white frosted face centres, leaf-green cores and edged intense blackberry-purple.

Some crystals are colour-zoned displaying bands of blackberry, cranberry, mauve-red, deep purple and green. Crystals may have smooth glassy surfaces or intricate mosaic growth patterns.