Fluorite

This is one of those off-matrix twinned Fluorite crystals which wonderfully displays the subtle yet distinct colour zoning that this most famous of localities is renowned for. From The Bull Vein at Lady Annabella mine, close to the village of Eastgate, these delightful, colour-zoned interpenetrant twins have mirror-smooth faces and razor-sharp edges to 2.5 cm and sit acutely angled to each other on their common, milky-lemon-white translucent roughly cleaved base. The crystals vary between translucent and semi-transparent and are ginger-lemon throughout. Their edges however display at least five distinct and parallel coloured bands progressing from lemon, through colourless, blueish-grey and marine-green to a core of concentrically nested yellow phantoms. In LWUV the crystal edges fluoresce bright whitish-lavender forming an angular outer framework, while the faces within this lattice are a slightly more subdued purple.

The Lady Annabella mine began specimen recovery operations in July 2020 within the former Eastgate Quarry, previously known as the Blue Circle Cement Quarry. This quarry began in the early 1960s, working an exposure of the Great Limestone, a major formation of Carboniferous age (Pendleian Substage), found across much of Northern England. Following uplift and fracturing, subsequent Fluorite mineralisation pervaded this area of County Durham, in the form of sub-vertical veins and near-horizontal metasomatic flats. Metasomatism is the chemical alteration of rock by hydrothermal fluids. Over the past 55 years, Fluorite from this quarry has become famous amongst collectors for its wide range of colours, colour variations and zonation. In just its first five months of operation, the Lady Annabella mine has produced a magnificent range of Fluorite specimens, many of which are colour variants and mixtures never before seen at this locality, nor even in the other famous mines throughout the Weardale Valley.