Natural Fluorescent Hackmanite Sphere 303g 58mm

A polished hackmanite sphere of 58mm and 303g. In white light the surface shows a pale white-grey base with distributed patches of soft purple-lavender, areas of grey-blue feldspar, and scattered rust-brown iron oxide inclusions. The purple-lavender hackmanite zones are somewhat more prominent across this sphere's surface than on the 291g companion at the same diameter. The pink-lavender zones are the hackmanite in its tenebrescent state. Under longwave UV (365nm) the display is a vivid multi-color response: the hackmanite zones emit bright orange-red covering a large and well-distributed portion of the surface, with the feldspar matrix glowing blue-teal in the surrounding areas and darker non-fluorescent patches providing contrast. The orange coverage on this sphere is more extensive than on the 291g companion.

Tenebrescence is hackmanite's reversible photochromic shift: white or pale grey after time in ordinary light, pink to violet after UV or sunlight, bleaching back in ordinary light. The purple-lavender zones visible in daylight are the tenebrescent state developed through ambient light during photography. At 303g this sphere is slightly heavier than the 291g companion despite the same diameter, indicating a denser mineral distribution; the greater orange coverage in the 365nm photo corresponds to the higher hackmanite content relative to non-fluorescing matrix. From Badakhshan, Afghanistan.

Natural hackmanite sphere, 58mm, tenebrescent, Afghanistan.