Trevorite

Trevorite is a very rare nickeliferous mineral belonging to the spinel group. It has the chemical formula NiFe³⁺O₄. It is a black mineral with the typical spinel properties of crystallising in the cubic system, black streaked, infusible and insoluble in most acids.

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There is at least partial solid solution between trevorite and magnetite, with many magnetites from ultramafic rocks contaning at least trace amounts of Ni. Fe²⁺ and Mg²⁺ may substitute for Ni in trevorite.

It is named after Major Tudor Gruffydd Trevor who was a mining inspector in South Africa.

References

• Deer, W. A.; R. A. Howie, and J. Zussman (1992). An Introduction to the Rock-forming Minerals. Harlow, Essex: Longman, pp. 559-563. ISBN 0-470-21809-6. 
• webmineral.com entry