Hanksiteis asulfate mineral,distinguished as one of only a handful that contain bothcarbonateandsulfateions(asulfate carbonate). It has the chemical formulaNa22K(SO4)9(CO3)2Cl.
| Hanksite | |
|---|---|
 Hanksite crystal fromSearles Lake | |
| General | |
| Category | Sulfate minerals,sulfate carbonate |
| Formula (repeating unit) | Na22K(SO4)9(CO3)2Cl |
| IMA symbol | Hks[1] |
| Strunz classification | 7.BD.30 |
| Crystal system | Hexagonal |
| Crystal class | Dipyramidal (6/m) H–M symbol:(6/m) |
| Space group | P63/m |
| Unit cell | a= 10.465(21) Å c= 21.191(43) Å;Z= 2 |
| Identification | |
| Color | Colorless to pale yellow, may be grayish green due to clay inclusions |
| Crystal habit | Occurs as short prismatic to tabular hexagonal crystals |
| Cleavage | Good on {0001} |
| Fracture | Uneven |
| Tenacity | Brittle |
| Mohs scalehardness | 3–3.5 |
| Luster | Vitreous to dull |
| Streak | White |
| Diaphaneity | Transparent to translucent |
| Specific gravity | 2.562 |
| Optical properties | Uniaxial (−) |
| Refractive index | nω= 1.481,nε= 1.461 |
| Birefringence | δ = 0.020 |
| Ultravioletfluorescence | Pale yellow under LW UV |
| Solubility | Readily soluble in water |
| References | [2][3][4] |
Occurrence
editIt was first described in 1888 for an occurrence in Searles Lake, California, and named for American geologistHenry Garber Hanks.[3][4]Hanksite is normally found incrystalform asevaporitedeposits. Hanksite crystals are large but not complex in structure. It is often found inSearles Lake,Soda Lake,Mono Lake,and inDeath Valley.At its deposits inSan Bernardino County, Californiahanksite is commonly found beneath the surface embedded in mud or in drill cores (Palache et al., 1960). It is associated withhalite,borax,trona,andaphthitaliteat the Searles Lake locality.[2]It is also associated with borax mining in the Soda Lake area.[citation needed]
Physical characteristics
editHanksite can be colorless, white, gray, green, or yellow, and is transparent or translucent. The mineral's hardness is approximately 3 to 3.5. Thespecific gravityis approximately 2.5 (slightly below average). It is salty to the taste and sometimes glows pale yellow inultravioletlight. Typical growth habits are hexagonal prisms or tabular with pyramidal terminations. Thestreakof Hanksite is white. It can containinclusionsofclaythat the crystal formed around while developing.
Similar minerals
edit
References
edit- ^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.S2CID235729616.
- ^abHandbook of Mineralogy.
- ^abMindat.org.
- ^abWebmineral data.
Bibliography
edit- Palache, P.; Berman H.; Frondel, C. (1960). "Dana's System of Mineralogy, Volume II: Halides, Nitrates, Borates, Carbonates, Sulfates, Phosphates, Arsenates, Tungstates, Molybdates, Etc. (Seventh Edition) "John Wiley and Sons, Inc., New York, pp. 628-629.