Megacyclite
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About Megacyclite
Formula:
Na8KSi9O18(OH)9 · 19H2O
Colour:
Colorless
Lustre:
Vitreous, Sub-Vitreous
Hardness:
2
Specific Gravity:
1.82
Crystal System:
Monoclinic
Name:
The name is from the Greek for 'large' and 'cyclical', alluding to the structure of large, ringlike groups consisting of 18Si04 tetrahedra.
Type Locality:
This page provides mineralogical data about Megacyclite.
Classification of Megacyclite
Approved
8/E.24-10
9.CP.10
9 : SILICATES (Germanates)
C : Cyclosilicates
P : 12-membered and larger rings
9 : SILICATES (Germanates)
C : Cyclosilicates
P : 12-membered and larger rings
62.1.2.1
62 : CYCLOSILICATES Eight-Membered Rings
1 : Eight-Membered Rings with 8-membered and larger rings
62 : CYCLOSILICATES Eight-Membered Rings
1 : Eight-Membered Rings with 8-membered and larger rings
Physical Properties of Megacyclite
Vitreous, Sub-Vitreous
Transparency:
Transparent
Colour:
Colorless
Streak:
White
Hardness:
2 on Mohs scale
Cleavage:
Perfect
Perfect {100},less perfect {001}
Perfect {100},less perfect {001}
Fracture:
Step-Like
Density:
1.82(5) g/cm3 (Measured) 1.87 g/cm3 (Calculated)
Optical Data of Megacyclite
Type:
Biaxial (-)
RI values:
nα = 1.460 nβ = 1.478 nγ = 1.481
2V:
Measured: 44° , Calculated: 44°
Max Birefringence:
δ = 0.021

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:
Moderate
Dispersion:
r > v strong
Chemical Properties of Megacyclite
Formula:
Na8KSi9O18(OH)9 · 19H2O
IMA Formula:
KNa8Si9O18(OH)9 · 19H2O
Crystallography of Megacyclite
Crystal System:
Monoclinic
Cell Parameters:
a = 24.91 Å, b = 11.94 Å, c = 14.92 Å
β = 94.47°
β = 94.47°
Ratio:
a:b:c = 2.086 : 1 : 1.25
Unit Cell V:
4,424.09 ų (Calculated from Unit Cell)
Type Occurrence of Megacyclite
Place of Conservation of Type Material:
Mining Institute, St..Petersburg, 2066/1.
A.E. Fersman Mineralogical Museum, Academy of Science, Moscow, Russia, p733/2.
A.E. Fersman Mineralogical Museum, Academy of Science, Moscow, Russia, p733/2.
Synonyms of Megacyclite
Other Language Names for Megacyclite
Related Minerals - Nickel-Strunz Grouping
9.CP.05 | Traskite | Ba21Ca(Fe2+,Mn,Ti)4(Ti,Fe,Mg)12(Si12O36)(Si2O7)6(O,OH)30Cl6·14H2O | Hex. |
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 Megacyclite
Reference List:
Sort by Year (asc) | by Year (desc) | by Author (A-Z) | by Author (Z-A)
Khomyakov, A.P., Necheljustov, G.N., Yamnova, N.A., Pushcharovsky, D.Y. (1993) Megacyclite Na8KSi9O18(OH)9·19H2O — a new mineral. Zapiski Vserossijskogo Mineralogicheskogo Obshchestva: 122(1): 125-128.
Jambor, J.L., Roberts, A.C., Vanko, D.A. (1994) New mineral names. American Mineralogist: 79: 1009-1014.
New Minerals (1997), New Minerals 1990-1994.
Zubkova, N.V., Pekov, I.V., Chukanov, N.V., Listsin, D.V., Rabadanov, M.K., Pushcharovsky, D.Y. (2007) New data on megacyclite. New Data on Minerals. Moscow: 42: 81-92.
Krivovichev, S.V. (2013) Structural complexity of minerals: information storage and processing in the mineral world. Mineralogical Magazine: 77: 275-326.
Zubkova, N.V., Pekov, I.V., Pushcharovsky, D.Y. (2014) A review of crystal chemistry of natural silicates of alkaline elements in the light of new structural data. Mineralogical Magazine: 78: 253-265.
Internet Links for Megacyclite
mindat.org URL:
https://www.mindat.org/min-2626.html
Please feel free to link to this page.
Please feel free to link to this page.
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Localities for Megacyclite
Locality List




All localities listed without proper references should be considered as questionable.
Russia (TL) | |
| Am Min 79:1011; Pekov, I. (1998) Minerals First discovered on the territory of the former Soviet Union 369p. Ocean Pictures, Moscow |
| Pekov I.V., Zubkova N.V., Filinchuk Ya.E., Chukanov N.V., Zadov A.E., Pushcharovsky D.Yu., Gobechiya E.R. (2010): Shlykovite, KCa[Si4O9(OH)]·3H2O, and cryptophyllite, K2Ca[Si4O10]·5H2O, two new mineral species from the Khibiny alkaline complex, Kola Peninsula, Russia. Zapiski RMO, 139(1), 37-50. |
| Pekov I.V.. et al. (2009) Egorovite Na4[Si4O8(OH)4]·7H2O - new mineral from Lovozero alkaline massif (Kola peninsula) - Zapiski RMO, v. 138, №3, pp. 82-89 (in Rus.) |
Palitra pegmatite, Karnasurt mine, Kedykverpakhk Mt, Lovozero Massif, Murmansk Oblast, Russia