Fluocerite-(La) | |
---|---|
General | |
Category | Mineral |
Formula (repeating unit) | (La,Ce)F3 |
Strunz classification | 03.AC.15 (03) |
Dana classification | 09.03.04.02 (09) |
Crystal system | Trigonal |
Crystal class | Hexagonal scalenohedral |
Space group | P3c1 (No. 165) |
Unit cell | 328.80 ų (Calculated from Unit Cell) |
Identification | |
Formula mass | 196.02 |
Colour | Greenish-yellow |
Crystal habit | Platy, tabular |
Cleavage | Indistinct, Imperfect |
Mohs scale hardness | 4-5 |
Luster | Vitreous |
Streak | White |
Diaphaneity | Transparent to translucent |
Density | 5.93 |
Birefringence | 0.006 |
Fluocerite-(Ce) | |
---|---|
General | |
Category | Mineral |
Formula (repeating unit) | (La,Ce)F3 |
Strunz classification | 3/A.10-20 |
Dana classification | 9.3.4.1 |
Crystal system | Trigonal |
Crystal class | Hexagonal Scalenohedral |
Unit cell | 320.86 ų (Calculated from Unit Cell) |
Identification | |
Formula mass | 196.99 |
Colour | Light yellow; darkening to yellow- and red-brown; colourless to pale pink (transmitted light) |
Crystal habit | Massive, Primsatic |
Cleavage | Distinct/Good |
Fracture | Irregular/Uneven, Splintery, Sub-Conchoidal |
Tenacity | Brittle |
Mohs scale hardness | 4.5-5 |
Luster | Vitreous, Resinous, Pearly |
Streak | Yellow-white |
Diaphaneity | Transparent to translucent |
Specific gravity | 5.93 - 6.14 |
Density | 5.93 - 6.14 g/cm3 (Measured) |
Birefringence | 0.005 - 0.007 |
Fluocerite, also known as tysonite, is a mineral consisting of cerium and lanthanum fluorides, with the chemical formula (Ce,La)F3.[1][2] The end members are classified as two different mineral types depending on the cation, fluocerite-(Ce) and fluocerite-(La), corresponding respectively to lanthanum trifluoride and cerium trifluoride. Both crystallize in the trigonal system.[3]
Fluocerite-(Ce) was first described (without the Ce) in 1845 from hydrothermal veins in granite in Sweden.[4] Fluocerite-(La) was first described in 1969 from the type locality in central Kazakhstan.[3] The name tysonite was given in 1880 to the same type of mineral found in Colorado.[5][6] Tysonite-type structure is used for rare-earth fluorides with the P3c1 space group structure.[7]
References
[edit]- ^ "Fluocerite-(La) Mineral Data". webmineral.com. Retrieved 2021-02-12.
- ^ "Fluocerite-(Ce) Mineral Data". webmineral.com. Retrieved 2021-02-12.
- ^ a b "Fluocerite-(La)". www.mindat.org. Retrieved 2021-02-12.
- ^ "Fluocerite-(Ce)". www.mindat.org. Retrieved 2021-02-12.
- ^ Geijer, Per (1921-01-01). "On Fluocerite and Tysonite". Geologiska Föreningen i Stockholm Förhandlingar. 43 (1–2): 19–23. doi:10.1080/11035892109443886. ISSN 0016-786X.
- ^ Allen, Oscar D., and W. J. Comstock. "Bastnaesite and tysonite from Colorado." American Journal of Science 3.113 (1880): 390-393.
- ^ Dudney, Nancy J.; West, William C.; Nanda, Jagjit (2015-07-09). Handbook Of Solid State Batteries (Second ed.). World Scientific. ISBN 978-981-4651-91-2.