Mineral Species
Yvonite
Type Locality
No
Composition
Cu(AsO3OH)·2H2O
Crystal System
Triclinic
Status at Tsumeb
Questionable
Entry Number
Species; TSNB378
General Notes
Yvonite from Tsumeb was first identified on a specimen in the Pinch Collection. The specimen was taken to the University of Arizona during the 2014 Tucson mineral show, where it was identified as yvonite by Raman spectroscopy (Bill Pinch, pers. comm. to M. Southwood 2014). Yvonite is included in the list of Tsumeb species published by Von Bezing et al. (2014; page 441), although without any elaboration. However, Von Bezing et al. (2016) comment that yvonite can "…now be confirmed for Tsumeb (W. Pinch, pers. comm. 2016)".
Yvonite from Tsumeb is listed as "believed valid" on Mindat, citing Von Bezing et al. (2016) as the source (https://www.mindat.org/locentry-1091738.html; accessed July 2022).
The Pinch specimen is now in the collections at Harvard University (catalogue number MGMH 2020.7.2043). The putative yvonite occurs as a thin, blue, botryoidal coating on the surface of tennantite-rich massive sulphide ore. Based on similar material in the Feinglos Collection, also at Harvard (MGMH 2022.4.6333), associated minerals are geminite, lindackerite, olivenite and an as yet uncharacterised zinc arsenate (Mark Feinglos, pers. comm. to M. Southwood, October 2019).
However, re-analysis of the "yvonite" on the Feinglos specimen has indicated that the original identification may have been erroneous and that the blue mineral may be something closely related to calcioandyrobertsite (Mark Feinglos, pers. comm. to M. Southwood, October 2019).
Yvonite has subsequently been identified by Joy Désor as blue microcrystalline aggregates on massive sulphide and a specimen of this material is in the collection of Paul de Bondt (https://www.mindat.org/photo-1274860.html ; accessed March 2023). The means of identification for this material is not stated, however, and given the uncertainty surrounding the Pinch and Feinglos specimens, the occurrence of yvonite at Tsumeb is considered questionable pending further investigation.
Associated Minerals
geminite (?); lindackerite (?); olivenite (?); tennantite-(Zn) (?)
