Hafnon

 Hafnon is a hafnium nesosilicate mineral, chemical formula (Hf,Zr)SiO4 or (Hf,Zr,Th,U,Y)SiO4.[1] In natural zircon ZrSiO4 part of the zirconium is replaced by the very similar hafnium and so natural zircon is never pure ZrSiO4. A zircon with 100% hafnium substitution can be made synthetically and is hafnon.

Hafnon
Hafnon.jpg
Very small brown single crystals of hafnon from Bernic Lake, Lac-du-Bonnet District, Manitoba, Canada
General
CategoryNesosilicates
Formula
(repeating unit)		Hafnium silicate (HfSiO4)
Strunz classification09.AD.30
Dana classification51.05.02.02
Crystal systemTetragonal
Crystal classDitetragonal Dipyramidal (4/mmm )
H-M symbol: (4/m 2/m 2/m)
Space groupI41/amd
Unit cella = 6.5725(7) Å, c = 5.9632(4) Å=; Z = 4
Identification
ColourOrange-red,brownish yellow, rarely colourless
Crystal habitEuhedral to irregular crystals
Cleavage{???} Indistinct
Mohs scale hardness7.5
LusterVitreous
Streakgrey white
DiaphaneityTransparent
Density6.97
Optical propertiesUniaxial (+)
Refractive indexnω = 1.930 - 1.970 nε = 1.980 - 2.030
Birefringenceδ = 0.050
Common impuritiesOften zoned with zircon. Forms part of zircon-hafnon series

Hafnon occurs as transparent red to red orange tetragonal crystals with a hardness of 7.5.[2][3]

Hafnon occurs naturally in tantalum-bearing granite pegmatites in the Zambezia district, Mozambique and in weathered pegmatites at Mount Holland, Western Australia.[4] It has also been reported from locations in Ontario, Quebec and Manitoba, Canada; North Carolina, United States; and in Zimbabwe.[2]

This article uses material from the Wikipedia article
 Metasyntactic variable, which is released under the 
Creative Commons
Attribution-ShareAlike 3.0 Unported License

Note

This article uses material from the Wikipedia article
 Metasyntactic variable, which is released under the 
Creative Commons
Attribution-ShareAlike 3.0 Unported License.