Jerrygibbsite

Jerrygibbsite
Jerrygibbsite (pink) found in New Jersey
General
CategoryNesosilicates
Formula
(repeating unit)
(Mn,Zn)9(SiO4)4(OH)2
IMA symbolJgb[1]
Strunz classification9.AF.70
Crystal systemOrthorhombic
Crystal classPyramidal (mm2)
H-M symbol: (mm2)
Space groupPbn21
Unit cella = 4.85, b = 10.7
c = 28.17 [Å]; Z = 4
Identification
ColorViolet-pink, with a brownish tinge
Crystal habitInterlocking anhedral crystals
CleavageImperfect on {001}
Mohs scale hardness5.5
LusterVitreous
StreakLight pink
DiaphaneityAlternating transparent and translucent lamellae
Specific gravity4.00
Optical propertiesBiaxial (−)
Refractive indexnα = 1.772 nβ = 1.783 nγ = 1.789
Birefringenceδ = 0.017
2V angleMeasured: 72°
References[2][3]

Jerrygibbsite is a rare silicate mineral with the chemical formula (Mn,Zn)9(SiO4)4(OH)2. Jerrygibbsite was originally discovered by Pete J. Dunn in 1984, who named it after mineralogist Gerald V. Gibbs (born 1929). It has only been reported from the type locality of Franklin Furnace, New Jersey, United States, and in Namibia's Otjozondjupa region. Jerrygibbsite is member of the leucophoenite family of the humite group. It is always found with these two minerals. It is a dimorph of sonolite.

  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. ^ Mindat.org
  3. ^ Handbook of Mineralogy