Gottlobite

Gottlobite
General
CategoryHydroxide mineral, Vanadate mineral, Arsenate mineral
Formula
(repeating unit)
CaMg(VO4,AsO4)(OH)
IMA symbolGot[1]
Strunz classification08.BH.35
Dana classification41.05.01.10
Crystal systemOrthorhombic
Space groupP222
Unit cella = 7.501(4) Å; b = 9.010(7) Å; c = 5.941(4) Å; Z = 4, V = 401.5Å3
Identification
Formula mass205.20 gm
ColorOrange to orange-brown
Crystal habitIsometric to tabular crystals
TwinningNot observed
CleavageNot observed
FractureConchoidal to irregular
TenacityBrittle
Mohs scale hardness4.5
LusterVitreous to adamantine
StreakLight brownish
DiaphaneityTransparent
Specific gravity3.46 g/cm3 (calculated)
Optical propertiesBiaxial negative
Refractive indexnα = 1.797 nβ = 1.805-1.815 nγ = 1.828
PleochroismMedium strong with X = orange-brown, Y = pale yellowish brown, and Z = orange-brown
GroupVandates and arsenates
References[2][3][4]

Gottlobite, CaMg(VO4,AsO4)(OH), is a mineral found as isolated crystals or isometric grains of orange or orange-brown color. The size of the crystals are a half millimeter in diameter and are part of the orthorhombic crystal system. Gottlobite forms a solid solution with adelite, which is an end member composition of CaMg(VO4)(OH), as well as being classified in the adelite group. Gottlobite is also part of the vanadates and arsenates group. With these characteristics, it is similar to the minerals tangeite and austinite by X-ray diffraction methods.[4]

  1. ^ 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.
  2. ^ Gottlobite. Webmineral. Retrieved on 2017-11-24.
  3. ^ [1] Journal. Retrieved on 2017-11-17.
  4. ^ a b Witzke, T.; Steins, M.; Doering, T.; Kolitsch, U. (2000). "Gottlobite, CaMg(VO4, AsO4)(OH), a new mineral from Friedrichroda, Thuringia, Germany". Neues Jahrbuch für Mineralogie - Monatshefte. Monatshefte 2000: 444–454.