Rhodesite
This page is currently not sponsored. Click here to sponsor this page.
About Rhodesite
Formula:
KHCa2Si8O19 · 5H2O
Colour:
White
Lustre:
Silky
Hardness:
3 - 4
Specific Gravity:
2.27 - 2.36
Crystal System:
Orthorhombic
Name:
Named after Cecil John Rhodes (1853-1902), British colonial statesman and financier of the Rhodes University, South Africa. He ran the British South Africa Company, which operated in a territory that bacame known as Rhodesia (named after him, now the countries of Zimbabwe and Zambia). He also found the De Beers diamond company. Do not confuse with Rhodizite.
Classification of Rhodesite
Approved, 'Grandfathered' (first described prior to 1959)
8/H.38-20
9.EB.05
9 : SILICATES (Germanates)
E : Phyllosilicates
B : Double nets with 4- and 6-membered rings
9 : SILICATES (Germanates)
E : Phyllosilicates
B : Double nets with 4- and 6-membered rings
72.5.1.1
72 : PHYLLOSILICATES Two-Dimensional Infinite Sheets with Other Than Six-Membered Rings
5 : Two-Dimensional Infinite Sheets with Other Than Six-Membered Rings with corrugated and complex layers
72 : PHYLLOSILICATES Two-Dimensional Infinite Sheets with Other Than Six-Membered Rings
5 : Two-Dimensional Infinite Sheets with Other Than Six-Membered Rings with corrugated and complex layers
14.6.7
14 : Silicates not Containing Aluminum
6 : Silicates of Ca with alkali or Mg or both
14 : Silicates not Containing Aluminum
6 : Silicates of Ca with alkali or Mg or both
Pronounciation of Rhodesite
Pronounciation:
Play | Recorded by | Country |
---|---|---|
Jolyon & Katya Ralph | United Kingdom |
Physical Properties of Rhodesite
Silky
Transparency:
Transparent, Translucent
Colour:
White
Hardness:
3 - 4 on Mohs scale
Cleavage:
Distinct/Good
Good on {100}
Good on {100}
Density:
2.27 - 2.36 g/cm3 (Measured) 2.26 g/cm3 (Calculated)
Optical Data of Rhodesite
Type:
Biaxial (+)
RI values:
nα = 1.501 - 1.504 nβ = 1.506 - 1.508 nγ = 1.513 - 1.518
2V:
Calculated: 68.1°
Max Birefringence:
δ = 0.012 - 0.014

Image shows birefringence interference colour range (at 30µm thickness)
and does not take into account mineral colouration.
and does not take into account mineral colouration.
Surface Relief:
Low
Dispersion:
relatively strong
Chemical Properties of Rhodesite
Formula:
KHCa2Si8O19 · 5H2O
Common Impurities:
Al,Fe,Mg,Na
Crystallography of Rhodesite
Crystal System:
Orthorhombic
Class (H-M):
mmm (2/m 2/m 2/m) - Dipyramidal
Cell Parameters:
a = 23.42 Å, b = 6.55 Å, c = 7.01 Å
Ratio:
a:b:c = 3.576 : 1 : 1.07
Unit Cell V:
1,075.34 ų (Calculated from Unit Cell)
Z:
2
Morphology:
Matted silky fibers, flattened rosettes, irregular segregations, crusts.
Type Occurrence of Rhodesite
Other Language Names for Rhodesite
Related Minerals - Nickel-Strunz Grouping
9.EB.05 | Macdonaldite | BaCa4Si16O36(OH)2 · 10H2O | Orth. |
9.EB.10 | Delhayelite | (Na,K)10Ca5Al6Si32O80(Cl2,F2,SO4)3 · 18H2O | Orth. |
9.EB.10 | Hydrodelhayelite | KCa2AlSi7O17(OH)2 · 6H2O | Orth. |
9.EB.15 | Monteregianite-(Y) | (Na,K)6(Y,Ca)2Si16O38 · 10H2O | Mon. 2/m |
9.EB.20 | Carletonite | KNa4Ca4Si8O18(CO3)4(OH,F) · H2O | Tet. 4/mmm (4/m 2/m 2/m) : P4/mbm |
Related Minerals - Dana Grouping (8th Ed.)
72.5.1.2 | Monteregianite-(Y) | (Na,K)6(Y,Ca)2Si16O38 · 10H2O | Mon. 2/m |
72.5.1.3 | Macdonaldite | BaCa4Si16O36(OH)2 · 10H2O | Orth. |
72.5.1.4 | Delhayelite | (Na,K)10Ca5Al6Si32O80(Cl2,F2,SO4)3 · 18H2O | Orth. |
72.5.1.5 | Hydrodelhayelite | KCa2AlSi7O17(OH)2 · 6H2O | Orth. |
Related Minerals - Hey's Chemical Index of Minerals Grouping
14.6.1 | Combeite | Na4.5Ca3.5Si6O17.5(OH)0.5 | Trig. 3m (3 2/m) : R3m |
14.6.2 | Pectolite | NaCa2Si3O8(OH) | Tric. 1 : P1 |
14.6.3 | Pectolite-M2abc | NaCa2[HSi3O9] | |
14.6.4 | Denisovite | K14+x(Ca,Na,Mn,Fe)48[Si60O162]F16(Ox,OH4−x)·2H2O | Mon. |
14.6.5 | Tokkoite | K2Ca4[Si7O18(OH)](OH,F) | Tric. |
14.6.6 | Mountainite | KNa2Ca2[Si8O19(OH)] · 6H2O | Mon. 2/m : P2/b |
14.6.8 | Miserite | K1.5-x(Ca,Y,REE)5(Si6O15)(Si2O7)(OH,F)2 · yH2O | Tric. |
14.6.9 | Åkermanite | Ca2Mg(Si2O7) | Tet. 4 2m : P4 21m |
14.6.10 | Monticellite | CaMgSiO4 | Orth. |
14.6.11 | Merwinite | Ca3Mg(SiO4)2 | Mon. 2/m : P21/b |
14.6.12 | Diopside | CaMgSi2O6 | Mon. 2/m : B2/b |
14.6.13 | Tremolite | ☐{Ca2}{Mg5}(Si8O22)(OH)2 | Mon. 2/m : B2/m |
Other Information
Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.
References for Rhodesite
Reference List:
Sort by Year (asc) | by Year (desc) | by Author (A-Z) | by Author (Z-A)
Mountain, E.D. (1957) Rhodesite, a new mineral from the Bultfontein mine, Kimberley. Mineralogical Magazine: 31: 607-610.
Gard, J.A., Taylor, H.F.W., Chalmers, R.A. (1957) An investigation of two new minerals: rhodesite and mountainite. Mineralogical Magazine: 31: 611-623.
Hesse, K.F., Liebau, F., Merlino, S. (1992) Crystal structure of rhodesite, HK1-xNax+2y Ca2-y(lB,3,22∞)[Si8O19]·(6-z)H2O, from three localities and its relation to other silicates with dreier double layers. Zeitschrift für Kristallographie: 199: 25-48.
Internet Links for Rhodesite
mindat.org URL:
https://www.mindat.org/min-3403.html
Please feel free to link to this page.
Please feel free to link to this page.
Search Engines:
External Links:
Mineral Dealers:
Localities for Rhodesite
Locality List




All localities listed without proper references should be considered as questionable.
Austria | |
| Postl, W. (1997); R. Exel: Die Mineralien und Erzlagerstätten Österreichs (1993) |
| Taucher, J. et al. (1989) |
| Postl, W. (1987); Exel, R. (1993) |
Germany | |
| Hesse K F, Liebau F, Merlino S (1992) Crystal structure of rhodesite, HK1-xNax+2y Ca2-y(lB,3,22∞)[Si8O19]·(6-z)H2O, from three localities and its relation to other silicates with dreier double layers. Zeitschrift für Kristallographie 199, 25-48; Wittern: "Mineralfundorte in Deutschland", 2001 |
| |
| [Blass, G., Graf, H.W., Neue Mineralfunde - mineralogische Raritäten - aus der Vulkaneifel, Mineralien-Welt 7/5, 28, 1996] [A. Wittern: Mineralfundorte in Deutschland, Schweizerbart (Stuttgart), 2001] |
Italy | |
| Stoppa, F., Sharygin, V.V., and Cundari, A. (1997): Mineralogy and Petrology 61, 27-45.; Sharygin, V. V., Pekov, I. V., Zubkova, N. V., Khomyakov, A. P., Stoppa, F., & Pushcharovsky, D. Y. (2013). Umbrianite, K7Na2Ca2 [Al3Si10O29] F2Cl2, a new mineral species from melilitolite of the Pian di Celle volcano, Umbria, Italy. European Journal of Mineralogy, 25(4), 655-669. |
South Africa (TL) | |
| Mountain E D (1957) Rhodesite, a new mineral from the Bultfontein mine, Kimberley. Mineralogical Magazine 31, 607-610; Minerals of South Africa |
Ukraine | |
| Baranov, P., Shevchenko, S., Heflik, W., Natkaniec-Nowak, L., & Dumanska-Slowik, M. (2009). Jaspilite—the gemstone of Ukraine. The journal of gemmology and proceedings of the Gemmological Association of Great Britain, 31(5), 163. |
USA | |
| Gunnar Färber |
| Sheppard, R.A. and Gude, A.J. (1969a) Rhodesite from Trinity County, California. American Mineralogist: 54: 251-255; Barnes, I., J.B. Rapp & J.R. O’Neil (1972), Metamorphic assemblages and the direction of flow of metamorphic fluids in four instances of serpentinization: Contributions to Mineralogy and Petrology: 35: 264; Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 441, 442; www.mineralsocal.org. |
Caspar quarry, Bellerberg volcano, Ettringen, Mayen, Mayen-Koblenz, Rhineland-Palatinate, Germany