Bisbeeite (a synonym of Plancheite or Chrysocolla)
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Bisbeeite is named after Bisbee, Cochise County, Arizona, USA where it was first described.

Discovered in 1915; IMA status: Not Valid - Discredited (a synonym of Chrysocolla)

Chemistry

Chemical Formula:

CuSiO₃ • nH₂O

Hydrated Copper Silicate

More Information

Bisbeeite is a synonym of Chrysocolla.
For more information please see the Chrysocolla information page.
 

Synonyms:

Chrysocolla

Type Locality:

Shattuck Mine, Bisbee, Warren District, Mule Mts, Cochise County, Arizona, USA

Year Discovered:

1915

View mineral photos:

Bisbeeite Mineral Photos and Locations

More Information

Mindat.org

Bisbeeite is a poorly defined, secondary copper mineral. It was named after Bisbee, Cochise County, Arizona, USA where it was first discovered in 1915 at the Shattuck Mine. The new mineral was originally described by Dr. W. T. Schaller and he proposed the name Bisbeeite after the discovery locality. He noted that the composition was identical to Dioptase but that Bisbeeite had distinctive optical properties. However, Bisbeeite from the Grandview Mine, Arizona, as reported by Professor Austin F. Rogers in 1922, was found to be Cyanotrichite by Samuel G. Gordon in 1923.

Several subsequent studies indicated that Bisbeeite was not a valid species, but a variety of Plancheite (A. Schoep, 1930) or a variety of Chrysocolla (V. Billiet, 1942). In 1962, R. B. Laurent and R. Pierrot studied type material as well as material from an African locality arriving at the conclusion that it was indeed a valid species. Then in 1967 M. C. Van Oosterwyck-Gastuche studied what was said to be Bisbeeite from an African source only and she determined that it was a mixture of Chrysocolla and Plancheite, not a distinct species. Even though Bisbeeite from the type locality was not used in her studies, Bisbeeite was later discredited in 1977 by the Commission on New Minerals and Mineral Names (CNMMN) of the International Mineralogical Association (IMA). Bisbeeite from the type locality is not particularly rare and is present on many Shattuckite specimens. The difficulty is in acquiring reasonably pure material for study, as the Shattuckite replaced by Bisbeeite was often impure to start with. 

During the early 1990s Sid Williams, Richard Bideaux and Doug Graeme agreed that discrediting a species based on a study that did not involve the type material was not sufficient. Based on x-ray testing they conducted on five samples from the type locality, they were satisfied that Bisbeeite was viable as a distinct species. However, efforts to replicate the reported chemistry were complicated by impure material. Their "Bisbeeite" project was put on hold when Michael Fleischer dropped Bisbeeite from his comprehensive "Glossary of Mineral Species" (published by Minerological Record Inc.).

In their book Mineralogy of Arizona (third edition, 1995), the authors John W. Anthony, Sidney A. Williams, Richard A. Bideaux and Raymond W. Grant state: "we believe that the Morenci and Hardshell material may provide the basis for resurrecting Bisbeeite as a species." They were referring to mineral samples from the Morenci-Metcalf district, Greenlee County and the Hardshell mine, Patagonia district, Santa Cruz County, Arizona.

Bisbeeite may still be a valid species, but because of the inherent problem of impurities in the Bisbee material, it may be some time before the question of the validity of Bisbeeite as a species can be answered. So, depending on where you are reading about Bisbeeite and the publication date, Bisbeeite may be referred to as a distinct mineral species, or a synonym or variety of Chrysocolla or maybe even a synonym or variety of Plancheite. For now, the name Bisbeeite has been relagated to the status of a discredited species and merely being a synonym of Chrysocolla.

For more information please see the Chrysocolla information page.