Harmotome on Calcite (old UK rarity)

Item Description

A classic, old-time specimen of lustrous, pearlescent Harmotome crystals to 1 cm, on matrix that is partly Calcite, from the Bellsgrove Mine in Strontian, Scotland. Harmotome is a rare zeolite mineral and these bone-white, euhedral crystals are sharp and attractive. The intriguing aspect of this small cabinet piece is the orange fluorescence where the Harmotome crystals have been exposed. Such fluorescence is unheard of for Harmotome, but definitely in the realm of possibility for Calcite. So, is this an indication of a chemistry change for the Harmotome as it grew, or are these crystals an overgrowth of Harmotome on Calcite? Not entirely sure, but this is certainly fascinating. These pieces are part of a century-old Italian collection that was recently acquired. Seldom seen for sale!