Black Sphalerite on Quartz – Madan, Bulgaria | Ref. 56

Specimen description

This specimen combines black sphalerite with an important quartz crystallization. Several very dark sphalerite crystal aggregates stand out above a dense cluster of white to translucent quartz crystals of varying sizes and orientations.

Both minerals are clearly visible across the specimen, with a larger sphalerite crystallization particularly prominent in its upper section.

Sphalerite

Sphalerite, traditionally also known as blende, is a zinc sulphide whose formula can be written as (Zn,Fe)S, with iron occurring in variable proportions.

Its colour can vary considerably, from yellow or brown to much darker shades. Iron-rich sphalerite generally displays a very dark brown to black coloration.

Its hardness ranges from 3.5 to 4 on the Mohs scale.

Provenance

This specimen comes from Madan, Bulgaria, an important mining locality known for its associations of sulphide minerals and quartz. It was collected in 1996.

Dimensions and presentation

Stone dimensions: 135 × 90 × 45 mm.

Weight: 360 g.