Crystal System: Hexagonal
Status of Occurrence: Confirmed Occurrence - 1st UK recording
Distribution: Rare
Chemical Composition: Nickel hydrate antimony hydroxide
Chemical Formula: Ni[Sb5+(OH)6]2.6H2O
Method(s) of Verification: Hendrefelen Mine - XRD & EPMA (Natural History Museum); Mynydd Gorddu Mine - EPMA (Natural History Museum).

Chemical Group:

  • Antimonates and Antimonites

Geological Context:

  • Supergene: post-mining oxidation & weathering deposits
Platy bottinoite microcrystals from Hendrefelen Mine, Pontrhydygroes, Ceredigion, Wales. Image 1.5 mm across. S.A. Rust specimen. Image S.A. Rust, © S.A. Rust.
Introduction: bottinoite is a secondary mineral, formed through the alteration of nickel and antimony-bearing ore minerals, notably ullmannite. Bottinoite is typically formed in the post-mining supergene environment.
Occurrence in Wales: described as a new mineral species in 1992, the Welsh occurrences of bottinoite are limited to the Central Wales Orefield, where the few specimens so far discovered are microcrystalline.

Key Localities:

  • Gwaithgoch Mine, Pontrhydygroes, Ceredigion: a mineral visually resembling bottinoite occurs rarely within highly altered ullmannite-bearing veinstone (Bevins & Mason, 1997).
  • Hendrefelin Mine, Ysbyty Ystwyth, Ceredigion: well-developed pale green feathery sprays within cavities in highly altered ullmannite-chalcopyrite-galena bearing vein quartz were collected in 1989 by S. A. Rust and subsequently confirmed as bottinoite (Clark & Rust, 1993).
  • Mynyddgorddu Mine, Bontgoch, Ceredigion: bottinoite, initially discovered in 1992 from this locality by S. A. Rust, occurs encrusting cleavage planes on small masses of ullmannite enclosed in quartz with chalcopyrite and galena (Clark & Rust, 1993).


  1. Bevins, R.E. & Mason, J.S., 1997. Welsh metallophyte and metallogenic evaluation project: Results of a minesite survey of Dyfed and Powys. CCW Contract Science Report No. 156. National Museums & Galleries of Wales.
  2. Clark, A.M. & Rust, S.A., 1993. Bottinoite, a mineral new to Britain. Mineralogical Magazine. 57, 543-544.