Zektzerite | |
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General | |
Category | Inosilicate |
Formula (repeating unit) | LiNa(Zr,Ti,Hf)Si6O15 |
IMA symbol | Zek[1] |
Strunz classification | 9.DN.05 |
Crystal system | Orthorhombic |
Crystal class |
|
Space group | Cmca |
Identification | |
Formula mass | 529.66 g/mol |
Color | Colorless to pink, cream, or white; commonly zoned |
Crystal habit | Stout pseudohexagonal prisms |
Cleavage | {100} and {010} perfect |
Mohs scale hardness | 6 |
Luster | Vitreous to pearly |
Streak | White |
Diaphaneity | Translucent to transparent |
Specific gravity | 2.79 |
Optical properties | Biaxial (-) |
Refractive index | nα = 1.582 nβ = 1.584 nγ = 1.584 |
Ultraviolet fluorescence | Light yellow |
References | [2][3][4] |
The mineral zektzerite is a member of the tuhualite group and was first found in 1966 by Seattle mineralogist Benjamin Bartlett "Bart" Cannon. It was discovered in the Willow creek basin below Silver Star mountain in miarolitic cavities within the alkaline arfvedsonite granite phase of the Golden Horn batholith, Okanogan County, Washington.[3] It is named for Jack Zektzer (born 1936), mathematician and mineral collector of Seattle, Washington.[2]
The mineral was misidentified as alkali beryl (morganite) at that time. Subsequently, in September, 1975, additional specimens of the mineral were found in a "float boulder" (a glacial erratic, or dropstone) on the north side of Kangaroo Ridge at an approximate elevation of 6,500 feet (2,000 m); it was recognized that the material was not beryl.[5]