Acmite
A synonym of Aegirine
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Name:
First described by P. H. Ström (1821) from Rundemyr, Øvre Eiker, Buskerud, Norway for a mineral earlier mentioned shortly by Strøm (1784, as "crystalliseret hornsteen eller brun kantet og riflet Schoel i quarz"). Ström (1821) recognized it as a new mineral and suggested the name wernerin, after the German geologist, Abraham Gottlob Werner. But Berzelius (1821), who analyzed the mineral, named it achmit after the greek αχμη, spear point, due to the habit of the crystals.
Later, in 1834, H.M.T. Esmark found a new mineral on Låven, Langesundsfjorden, Norway which was described and given the name aegirine, (Berzelius 1835). Acmite and aegirine were first believed to be two separate species, one belonging to the amphiboles (acmite) and the other to the pyroxenes (aegirine). This was the case until 1871 when G. Tschermak put forward evidence that acmite and aegirine both belonged to the pyroxenes and are the same mineral. Acmite has been considered as a variety of aegirine (historically acmite had priority, so it should have been the other way around).
Later, in 1834, H.M.T. Esmark found a new mineral on Låven, Langesundsfjorden, Norway which was described and given the name aegirine, (Berzelius 1835). Acmite and aegirine were first believed to be two separate species, one belonging to the amphiboles (acmite) and the other to the pyroxenes (aegirine). This was the case until 1871 when G. Tschermak put forward evidence that acmite and aegirine both belonged to the pyroxenes and are the same mineral. Acmite has been considered as a variety of aegirine (historically acmite had priority, so it should have been the other way around).
French name for:
Both acmite and aegirine have been used as designations of pyroxenes close to NaFe3+Si2O6 in composition. Acmite has also often been used to refer to the brown variety with pointed terminations (usually {221} and {661}), while aegirine has been reserved for the green to green-black color varieties. Acmite has also been used to refer to the NaFe3+Si2O6 molecule, the so-called acmite-molecule in pyroxenes. In 1988 acmite was formally discredited as a separate species, and aegirine was used as a name for the end member NaFe3+Si2O6 (Morimoto 1988).
However, at the Rundemyr locality, the TL, both brownish and green-black varieties occur as intergrowths. Raade has shown that the green aegirine from Rundemyr has a higher content of FeO, TiO2, MnO and CaO and a lower content of Fe2O3 than the brown acmite (Raade 2010).
However, at the Rundemyr locality, the TL, both brownish and green-black varieties occur as intergrowths. Raade has shown that the green aegirine from Rundemyr has a higher content of FeO, TiO2, MnO and CaO and a lower content of Fe2O3 than the brown acmite (Raade 2010).
Unique Identifiers
Mindat ID:
4471 (as Acmite)
31 (as Aegirine)
31 (as Aegirine)
Long-form identifier:
mindat:1:1:4471:0 (as Acmite)
mindat:1:1:31:0 (as Aegirine)
mindat:1:1:31:0 (as Aegirine)
Similar Names
| Aceite | A rock classification type | |
| Afmite | A valid IMA mineral species | Al3(OH)4(H2O)3(PO4)(PO3OH) · H2O |
| Ammite | A synonym of 'Ooid-limestone' |
Internet Links for Acmite
mindat.org URL:
https://www.mindat.org/min-4471.html
Please feel free to link to this page.
Please feel free to link to this page.
References for Acmite
Reference List:
Ström, P. (1821) Undersökning af ett nytt Fossil [Examination of a new Fossil]. Kungliga Svenska vetenskapsakademiens handlingar, S. 3 Vol. 9. 160-163
Berzelius, Jöns Jacob (1821) Tillägg til föregående Afhandling [Addendum to previous paper]. Kungliga Svenska vetenskapsakademiens handlingar, S. 3 Vol. 9. 163-166
Schüller, Karl-Heinz (1958) Das Problem Akmit-Ägirin. Beiträge zur Mineralogie und Petrographie, 6 (2). 112-138 doi:10.1007/bf01084744
Cameron, Maryellen, Sueno, Shigeho, Prewitt, C. T., Papike, and J. J. (1973) High-temperature crystal chemistry of acmite, diopside, hedenbergite, jadeite, spodumene, and ureyite. American Mineralogist, 58 (7-8) 594-618
