| Category | Inosilicate |
|---|---|
| Formula | NaCa2(Mg3Ti4+Al)(Si6Al2)O22(O)2 |
| Imasymbol | Krs[1] |
| Strunz | 9.DE.10 |
| Dana | 66.01.03a.18 |
| System | Monoclinic |
| Class | Prismatic (2/m) (same H-M symbol) |
| Symmetry | C2/m |
| Color | Dark brown to black, yellow-brown, green-brown, or red-brown in thin section |
| Habit | Prismatic phenocrysts, granular aggregates |
| Twinning | Simple or multiple twinning parallel to {100} |
| Cleavage | Perfect on {110}, intersecting at 56° and 124° |
| Tenacity | Brittle |
| Mohs | 5–6 |
| Luster | Vitreous |
| Streak | Pale brownish-grey |
| Diaphaneity | Semitransparent |
| Gravity | 3.20–3.28 |
| Opticalprop | Biaxial (−) |
| Refractive | nα = 1.670–1.689 nβ = 1.690–1.741 nγ = 1.700–1.772 |
| Birefringence | δ = 0.030–0.083 |
| Pleochroism | Strong; X = yellow, yellow-brown; Y = red, red-brown; Z = deep brown, dark red-brown. |
| 2v | 66–82° |
| References | [2][3][4][5] |
Kaersutite is a dark brown to black double-chain calcic titanium-bearing amphibole mineral with formula: NaCa2(Mg3Ti4+Al)(Si6Al2)O22(O)2.[6]
Ferro-kaersutite is the divalent iron-rich endmember of the kaersutite group, with the iron replacing magnesium in the structure.[7]
Kaersutite occurs as phenocrysts in alkalic volcanic rocks, in nodules of peridotite and gabbro in alkalic basalts, and in syenites, monzonites, and carbonatite tuffs. Mineral associations include titanian augite, rhoenite, olivine, ilmenite, spinel, plagioclase, and titanian pargasite.[2]
It was first described in 1884 and is named for Qaersut (formerly Kaersut), Umanq district in northern Greenland.[3]
References
- ^ 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. S2CID 235729616
- ^ "Kaersutite". Handbook of Mineralogy. Retrieved 2024-03-21.
- ^ http://www.mindat.org/min-2129.html Mindat: Kaersutite
- ^ http://www.webmineral.com/data/Kaersutite.shtml Webmineral data
- ^ "IMA Master List". Archived from the original on 2015-01-05. Retrieved 2014-05-12.
- ^ "Nomenclature of the amphibole supergroup". Archived 2014-07-01 at the Wayback Machine.
- ^ Ferro-kaersutite on Mindat