Vitriol

Vitriol is chemical name for a class of chemical compound comprising sulfates of certain metals — originally, iron or copper. Those mineral substances were distinguished by their color, such as green vitriol for hydrated iron(II) sulfate and blue vitriol for hydrated copper(II) sulfate. [1]

5mm wide monocrystal of blue vitriol (cupric sulfate)

These materials were originally found as crystals formed by evaporation of groundwater that percolated through sulfide minerals and collected in pools on the floor of old mines. The word vitriol comes from the Latin word vitriolus, meaning "small glass", as those crystals resembled pieces of colored glass.

Oil of vitriol was an old name for concentrated sulfuric acid, which was obtained by the alchemist Jabir ibn Hayyan (c. 721–815 CE) through the dry distillation (pyrolysis) of vitriols. The name, shortened to vitriol, continued to be used for this viscous liquid long after the minerals came to be called "sulfates". The term vitriolic in the sense of "harshly condemnatory" is derived from the corrosive nature of this substance.

Vitriol Chemical Comment Formula
Black vitriol   a mixture[A] [Cu,Mg,Fe,Mn,Co,Ni]SO4·7H2O[B]
Blue vitriol/Vitriol of Cyprus/Roman vitriol[2] copper(II) sulfate pentahydrate CuSO4·5H2O
Green vitriol/Copperas iron(II) sulfate heptahydrate FeSO4·7H2O
Oil of vitriol/Spirit of vitriol sulfuric acid acid H2SO4
Red vitriol cobalt(II) sulfate heptahydrate CoSO4·7H2O
Sweet oil of vitriol diethyl ether not a sulfate CH3-CH2-O-CH2-CH3
Vitriol of argile/Vitriol of clay aluminium sulfate alum Al2(SO4)3
Vitriol of Mars iron(III) sulfate Ferric sulfate Fe2(SO4)3
White vitriol zinc sulfate heptahydrate ZnSO4·7H2O
A Many websites state "black vitriol is a mixture of iron sulfate and iron sulfite", but none gives a reference of any sort. The book, Chemistry, Inorganic & Organic, with Experiments, by Bloxam[3] is a published, reliable reference for the composition of black vitriol, and it states on page 513, "The formula of black vitriol may be written [CuMgFeMnCoNi]SO4·7H2O, the six isomorphous metals being interchangeable without altering the general character of the salt."
B "Any combination of these elements may be found in black vitriol."[3]


ReferencesEdit

  1. ^ "Vitriol" entry in the onlne Encyclopaedia Britannica. Accessed on 2020-08-28.
  2. ^ Roman vitriol on Chembk CAS Database
  3. ^ a b Bloxam, Charles Loudon; Bloxam, Arthur G.; Lewis, S. Judd (1913). "Copper, Cu = 63.57". Chemistry, Inorganic & Organic, with Experiments (Tenth ed.). Philadelphia: P. Blakiston's Son & Co. p. 513. The formula of black vitriol may be written [CuMgFeMnCoNi]SO4·7H2O, the six isomorphous metals being interchangeable without altering the general character of the salt.