Cesanite
Cesanite | ||
---|---|---|
Specific gravity 2.96-3.02 | | |
Optical properties | Uniaxial (-) | |
Refractive index | nω = 1.570 nε = 1.564 | |
Solubility | Slight in water | |
References | [2][3][4][5][6][7] |
Cesanite is the end member of the
History
Cesanite was first discovered in 1981 while the Italian National Electricity Board was doing exploratory drilling to examine a reservoir of heated brine to determine its potential as a geothermal energy source. When it was first found it was thought to be an apatite until after more thorough examination.[3]
Structure
Cesanite was originally determined by Tazzoli (1983) to be
Cesanite's crystal structure is made up of tetrahedra of
Physical properties
Cesanite veins are massive in habit and appear white in color with a silky luster. Individual crystals are colorless and transparent to translucent with a greasy luster. These crystals are elongated and begin with a pyramid on {101*0} that is distorted by a flatting that occurs down the length of the crystal which then extends down with two parallel faces until they are cut off by either a pinacoid or another pyramid.[3] According to the newest sources the unit-cell parameters of cesanite are a = 9.4630 and c = 6.9088 Å. In thin section cesanite remains transparent and has moderate birefringence.[3] In addition to is structure at room temperature, cesanite exhibits different crystal structures at different temperatures. Polymorphs occur at 425, 625, and 740 °C. These different forms are cause by expansion along the crystallographic axises as cesanite is heated.[9]
Geologic occurrence
Cesanite has been found in only three places to date. The original occurrence was observed as part of a
See also
References
- S2CID 235729616.
- ^ Mineralienatlas
- ^ a b c d e Cavarretta G., Mottana A., Tecce F. (1981) Cesanite, Ca2Na3[(OH)(SO4)3], a sulfate isotypic to apatite, from the Cesano Geothermal-Field (Lathium, Italy). Mineralogical Magazine, 44, 269-273.
- ^ a b c d Piotrowski A., Kahlenberg V., Fischer RX., etal. (2002) The crystal structures of cesanite and its synthetic analogue – A comparison. American Mineralogist, 87, 715-720.
- ^ Handbook of Mineralogy
- ^ Mindat.org
- ^ Webmineral data
- ^ Tazzoli V., (1983) The Crystal-structure of ceanite, CA1+XNA4-X(SO4)3(OH)X.(1-X)H2O, a sulfate isotypic to apatite. Mineralogical Magazine, 47, 59-63.
- ^ Deganello S., Artioli G. (1982) Thermal expansion of cesanite between 22 °C and 390 °C. Nues jahrbuch für Mineralogie, Monatshefte, 12, 565-568.
- ^ a b Onac BP, Mylroie JE, White WB. (2001) Mineralogy of cave deposits on San Salvador Island, Bahamas. Carbonates and Evaporites, 16, 8-16.
- ^ Onac BP., Verdes DS. (2003) Sequence of secondary phosphates deposition in a karst environment: evidence from Măgurici Cave (Romania). European Journal of Mineralogy, 15, 741-745.