Hackmanite (tenebrescent sodalite) 5g fluorescent

A compact hackmanite specimen at 5g with the hackmanite mineral making up most of the visible body. In white light the piece shows predominantly soft lavender-violet with a small section of pale beige host rock at the top. The hackmanite coverage is generous relative to the size, with little matrix interrupting the main face. After UV exposure the lavender deepens to a fuller purple-violet across the body. Under longwave UV (365nm) the stone glows strong orange across the full surface.

Tenebrescence is the reversible color change from white or pale grey in the dark-adapted state to pink or violet under UV light or sunlight, fading back in ordinary indoor light or darkness. The cycle repeats indefinitely without altering the mineral's structure. The high proportion of hackmanite relative to matrix in this piece means a clean, uninterrupted color shift with minimal pale areas: useful both as a study specimen and as a compact raw reference alongside polished examples. From Badakhshan, Afghanistan.

• Stone type: Natural hackmanite (tenebrescent sodalite)
• Weight: 5g
• Size: 24x17x11mm
• Color: Lavender (white light); purple (after UV)
• Fluorescence (365nm): Strong orange
• Cut: Rough
• Clarity: Opaque
• Treatment: Untreated
• Origin: Afghanistan

Natural hackmanite, tenebrescent sodalite, Afghanistan, sold loose.