A brief comment on Hawthorne (2023): “On the definition of distinct mineral species: A critique of current IMA-CNMNC procedures”

Abstract

AbstractIn this communication we present a brief response to Hawthorne (2023) who, in a paper in volume 87,doi.org/10.1180/mgm.2023.8(this journal), claims evidence for violations of the electroneutrality principle in mineral formulae derived through IMA–CNMNC procedures: i.e. the dominant-constituent rule, the valency-imposed double site-occupancy, the dominant-valency rule, and the site-total-charge approach (STC).His statement is not correct as the STC method is based on the end-member definition; thus, it cannot violate the requirements of an end-member, particularly the laws of conservation of electric charge. The STC was developed to address the shortcomings in the previous IMA–CNMNC procedures.The real question is: which method to use to define an end-member formula? Currently, there are two approaches: (1) STC, which first identifies the dominantend-membercharge arrangement and then leads to the dominantend-member composition; (2) the dominant end-member approach.