Cadmium Smithsonite

A striking and highly collectible specimen featuring lemon-yellow, translucent, bubbly botryoidal smithsonite from the historic Sheshodonnell Mine. The rounded crystal forms display a soft, velvety to matte surface lustre on the display side, with subtle translucency and rich cadmium-enhanced colour. The yellow hue is caused by minor cadmium content (averaging approximately 0.5% Cd), a feature that distinguishes this material from more common green or grey varieties. The botryoidal aggregates are tightly intergrown but highly aesthetic, forming a compact and attractive example of this classic occurrence. This specimen comes from the international collection of Peter Tarassoff.

The Sheshodonnell Mine was a tiny Victorian lead–zinc working active around 1862–63, where a narrow sphalerite vein was trenched over roughly 100 metres. Remarkably, the sphalerite was almost completely altered to botryoidal smithsonite in shades of yellow, green, grey, and white, creating what is widely regarded as the finest smithsonite occurrence in the British Isles. At the time of mining, the smithsonite was considered gangue and left on the spoil heaps; historical accounts note several tonnes visible on the dumps. Most of this material was later lost or bulldozed, and only a small amount was recovered from reworking of the dumps in the mid-20th century. Today, little remains at the site beyond a weathered spoil heap. High-quality specimens such as this are now extremely rare and represent true old-time classics from one of Europe’s most unusual carbonate replacement deposits.