Because of its color, Ahlfeld originally thought it was identical to the cobaltomenite from Cacheuta, described by Bertrand (1882), but Herzenberg determined that the red color was superficial only, and disappeared in nitric acid.
X-ray studies of ahlfeldite and cobaltomenite from Pacajake were published by Gattow and Lieder (1963).
Cobaltomenite occurs at Pacajake in solid solution with ahlfeldite; the name cobaltomenite is used when the cobalt content is greater than or equal to the nickel content.
Oxidation of penroseite gave rise to ahlfeldite (Ni), cobaltomenite (Co) and chalcomenite (Cu), while clausthalite gave the secondary lead minerals cerussite, molybdomenite, olsacherite and perhaps also wulfenite.
The stratiform deposits have yielded carrollite, linnaeite, trogtalite, cobaltomenite, heterogenite (both 3R and 2H polytypes), julienite, kolwezite and sphaerocobaltite.
Cobaltomenite has been found on the 2,400 level of the Musonoi-Extension mine.
Katanga Crescent Outside of Stratiform Vein-like Katanga Cresent Cobalt Cobalt Cobalt Deposits Deposits(*) Deposits(**) Primary Linnaeite Linnaeite Linnaeite Minerals Carrollite Carrollite Carrollite Cattierite Cobaltite Siegenite Trogtalite Penroseite Secondary Heterogenite-3R Heterogenite-3R Heterogenite-3R Minerals Heterogenite-2H Oursinite Kolwezite Comblainite Sphaerocobaltite Cobaltomenite Julienite * Shinkolobwe ** Kipushi
Other new finds from Utah include thin, bladed, centimeter-size crystals of hematite from the Creole mine, Beaver County (John Seibel Minerals); pale blue botryoidal smithsonite, calcite, rosasite, plattnerite and aurichalcite from the Hidden Treasure mine, north of Ophir, Tooele County, available from Jim McGlasson; rich purple crusts of cobaltomenite
on rock from the Parco mine group, Thompson District, Grand County, and microcrystals of pharmacosiderite, metazeunerite and olivenite from the Big Indian mine, near La Sal, San Juan County (Virgin Mining).