Schorl

Schorl from Mica Creek, Mount Isa, Queensland, Australia, measuring 88 × 41 × 36 mm and weighing 206 grams. A good elongated crystal from a locality better known among collectors for its pegmatite minerals generally.

Schorl is the iron-rich, near-black end member of the tourmaline group, a complex borosilicate typically forming elongated trigonal prisms with the characteristic rounded-triangular cross-section the group is known for. Mica Creek, near Mount Isa in north-west Queensland, sits within a pegmatite field associated with the region's granite intrusions, where boron-bearing residual fluids late in the granite's crystallisation combined with iron and aluminium to form Schorl alongside the mica the creek is named for.

A well-formed Schorl crystal from Mica Creek is a solid representative of north-west Queensland's pegmatite mineralogy, a part of the Mount Isa region's geology that gets far less attention than its famous base-metal orebody. This piece is from the David Vince Collection.