Cleiophane on quartz - Madan, Bulgaria | Ref. 605

This group of cleiophane on quartz, from the 9th September Mine in Madan, Bulgaria, shows several well-individualised crystals with distinct forms. The specimen displays well-developed crystallisation, with visible faces and reflections that vary depending on the orientation of the piece.

With dimensions of 59 mm in width and 34 mm in height, this specimen comes from an old collection dated 2008.

Cleiophane is a low-iron variety of sphalerite. It belongs to the general formula (Zn,Fe)S, with a lower iron content than in darker varieties. Its hardness is around 3.5 to 4 on the Mohs scale. This specimen from Madan illustrates this variety well, appreciated for the sharpness of its crystals and its occurrence in Bulgarian mineral associations.