Pharmacosiderite has an isometric crystal system, with yellowish-green, sharply defined cubecrystals. Its crystals are doubly refracting, and exhibit a banded structure in polarized light. When placed in ammoniumsolution, a crystal changes color to a distinguishing red. Upon placing it into dilute hydrochloric acid the original color is restored. This secondary origin mineral is normally formed in the oxidation zones of ore deposits. The alteration of arsenopyrite, tennantite and other primary arsenates can form pharmacosiderite. It can also form from the precipitation of hydrothermal solutions, but only rarely. It can be found in abundance in Cornwall, Hungary and the U.S. state of Utah. When it was first discovered, pharmacosiderite was known as cube ore. The present name, given by J. F. L. Hausmann in 1813, is made up of the Greek words for arsenic and iron, the two most significant consisting elements. Pharmakos means poison, which is related to arsenic, and sideros means iron. Pharmacolite and picropharmacolite, which are different arsenates, are not associated besides via nomenclature. Siderite, a carbonate mineral, only shares the common element iron with pharmacosiderite.
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This article incorporates text from a publication now in the public domain: Spencer, Leonard James (1911). "Pharmacosiderite". In Chisholm, Hugh (ed.). Encyclopædia Britannica. Vol. 21 (11th ed.). Cambridge University Press. p. 355.
March 17, 2024
pharmacosiderite, hydrated, basic, ferric, arsenate, with, chemical, formula, kfe4, aso4, molecular, weight, consists, elements, arsenic, iron, hydrogen, potassium, sodium, oxygen, mohs, hardness, about, that, finger, nail, specific, gravity, about, indistinct. Pharmacosiderite is a hydrated basic ferric arsenate with the chemical formula KFe4 AsO4 3 OH 4 6 7 H2O and a molecular weight of 873 38 g mol It consists of the elements arsenic iron hydrogen potassium sodium and oxygen It has a Mohs hardness of 2 to 3 about that of a finger nail Its specific gravity is about 2 7 to 2 9 has indistinct cleavage and is usually transparent or translucent It has a yellow or white streak and a yellow green brown or red color Its lustre is adamantine vitreous and resinous and it has conchoidal brittle and sectile fracture PharmacosideriteGeneralCategoryArsenate mineralsFormula repeating unit KFe4 AsO4 3 OH 4 6 7 H2OIMA symbolPmsd 1 Strunz classification8 DK 10Crystal systemIsometricCrystal classHextetrahedral 4 3m H M symbol 4 3m Space groupP4 3mIdentificationFormula mass873 38 g molColorGreens browns yellowsCrystal habitMassive to CrystallineCleavageDistinct on the 100 FractureBrittleMohs scale hardness2 5LusterAdamantineStreakyellowish greenDiaphaneitySubtransparent to subtranslucentDensity2 9 g cm3Ultraviolet fluorescenceNoneReferences 2 3 4 Pharmacosiderite has an isometric crystal system with yellowish green sharply defined cube crystals Its crystals are doubly refracting and exhibit a banded structure in polarized light When placed in ammonium solution a crystal changes color to a distinguishing red Upon placing it into dilute hydrochloric acid the original color is restored This secondary origin mineral is normally formed in the oxidation zones of ore deposits The alteration of arsenopyrite tennantite and other primary arsenates can form pharmacosiderite It can also form from the precipitation of hydrothermal solutions but only rarely It can be found in abundance in Cornwall Hungary and the U S state of Utah When it was first discovered pharmacosiderite was known as cube ore The present name given by J F L Hausmann in 1813 is made up of the Greek words for arsenic and iron the two most significant consisting elements Pharmakos means poison which is related to arsenic and sideros means iron Pharmacolite and picropharmacolite which are different arsenates are not associated besides via nomenclature Siderite a carbonate mineral only shares the common element iron with pharmacosiderite References edit nbsp Wikimedia Commons has media related to Pharmacosiderite Warr L N 2021 IMA CNMNC approved mineral symbols Mineralogical Magazine 85 3 291 320 Bibcode 2021MinM 85 291W doi 10 1180 mgm 2021 43 S2CID 235729616 Mineralienatlas Pharmacosiderite Pharmacosiderite mineral information and data Pharmacosiderite Mineral Data WebMineral Mineral Galleries MinDatAttribution nbsp This article incorporates text from a publication now in the public domain Spencer Leonard James 1911 Pharmacosiderite In Chisholm Hugh ed Encyclopaedia Britannica Vol 21 11th ed Cambridge University Press p 355 Retrieved from https en wikipedia org w index php title Pharmacosiderite amp oldid 1169983515, wikipedia, wiki, book, books, library,
