Stellerite

Stellerite from the Tambar Springs area, New South Wales, Australia, measuring 80 × 60 × 47 mm and weighing 189 grams. This is a locality specimen with an unusually detailed collecting history, linking it with Frank Godeny, Jon Mommers and Anne McDonald. Those connections make it an inviting piece for someone interested in Australian zeolites and the collectors who have sought them out.

Stellerite is a calcium-bearing zeolite, part of a family of hydrated aluminosilicates whose structures contain spaces that accommodate water and other components. Zeolites commonly develop during the alteration of volcanic rocks, where fluids can deposit minerals along openings. Stellerite is a distinct species, so its name adds a more precise mineralogical identity than a general zeolite label would provide.

Honey-toned crystals gather into an intergrown group with stepped faces and a broadly fan-like arrangement. Light catches the flatter surfaces at different angles, giving the cluster depth despite its fairly restrained colour. It is the organisation of those individual forms that rewards a closer look, especially where adjoining groups meet. The provenance records collection by Frank Godeny and associations with the Jon Mommers and Anne McDonald collections. Those named links are a substantial part of the specimen's interest. They bring a personal history to an otherwise technical mineral description, allowing the next collector to retain the story of the piece as well as its place in the zeolite family.