Epidote - Lustrous Gemmy Tabular Crystal, Shigar Valley, Pakistan

Epidote from the valleys of Baltistan has become the benchmark against which other localities are judged, and this single crystal from the Shigar Valley shows why. It is a thick, blade-like individual, self-standing and complete enough to be appreciated in the round, with the combination of body thickness and internal transparency that separates the better Pakistani Epidote from the opaque black splinters that make up most production. The architecture is classic for the species: a flattened prismatic crystal elongated along the b axis, its broad pinacoidal faces bounded by narrow, sharply defined side faces that step and ridge along the length of the crystal. Deep striations run parallel to the direction of elongation, and along one margin a series of subparallel blades has grown in close accretion, giving the piece a fluted, almost architectural profile. The termination is inclined and clean, with a small glassy face catching light at the apex. In ordinary reflected light the crystal reads as a very dark olive to near-black green, the colour that gives good Epidote its sombre authority. Turn it toward a light source, however, and the piece transforms. Light entering the thinner marginal blades passes through as warm amber and rich reddish-brown, and within the body of the crystal a broad zone glows pistachio to bronzy yellow-green, the celebrated epidote green that appears only where the crystal is thin enough or clear enough to transmit. That interplay of opaque exterior and luminous interior is the whole appeal of this material. Lustre is bright and vitreous to nearly resinous on the prism faces, and because those faces are striated rather than flat, the reflections travel along the crystal as it is rotated, breaking into a series of bright ribbons rather than a single flash. It is a crystal that rewards being handled under a directed light. The curator reports minor damage and chatter along the edges. This is worth stating plainly, because Epidote is a brittle species with perfect cleavage parallel to the basal plane, and the projecting edges and blade tips are exactly where handling and extraction take their toll. What matters here is that the principal faces and the termination remain intact and the transmission through the crystal is unaffected, so the specimen still delivers its central effect. As a complete, undamaged-in-the-essentials single crystal with genuine light transmission, this is a step above the run of Shigar Valley material, and fully terminated thick blades of this quality have grown noticeably harder to source as the classic Baltistan pockets have been worked out. Under a beam of directional light it shifts from a dark green monolith to a glowing amber-and-pistachio blade, which is precisely the drama collectors seek in this species.