Londonite Mineral Data (original) (raw)

General Londonite Information

Help on Chemical Formula: Chemical Formula:

CsAl4Be4(B,Be)12O28

Help on Composition: Composition:

Molecular Weight = 808.60 gm

Cesium 7.89 % Cs 8.36 % Cs2O

Potassium 1.84 % K 2.21 % K2O

Rubidium 0.95 % Rb 1.04 % Rb2O

Sodium 0.09 % Na 0.11 % Na2O

Lithium 0.02 % Li 0.04 % Li2O

Calcium 0.10 % Ca 0.14 % CaO

Manganese 0.07 % Mn 0.09 % MnO

Beryllium 5.57 % Be 15.47 % BeO

Aluminum 13.28 % Al 25.09 % Al2O3

Iron 0.07 % Fe 0.09 % FeO

Silicon 0.03 % Si 0.07 % SiO2

Boron 14.69 % B 47.31 % B2O3

Oxygen 55.40 % O

______ ______

100.00 % 100.03 % = TOTAL OXIDE

Help on Empirical Formula: Empirical Formula:

Cs0.48K0.38Rb0.09Na0.03Ca0.02Mn2+0.01Al3.98Li0.02Fe2+0.01Be4B10.99Si0.01BeO28

Help on Environment: Environment:

Found in miarolitic cavities. Cs-analogue of rhodizite.

Help on IMA Status: IMA Status:

Approved IMA 1999 (Dana # Added)

Help on Locality: Locality:

Central units or the Antandrokomby, Antsonombato, and Ampanivana granitic pegmatites in Central Madagascar. Link to MinDat.org Location Data.

Help on Name Origin: Name Origin:

Named for David London (1953-), petrologist at the University of Oklahoma, Oklahoma, USA.

Help on Synonym: Synonym:

IMA1999-014

Londonite Image

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Click Here for Larger Londonite Image Londonite Comments: A dodecahedral crystal of londonite. Location: Antandrokomby pegmatite, Manandona valley, Sahatany Valley, Betafo - Antsirabé region, Antananarivo Province, Madagascar.Scale: Crystal size 7 mm. © Thomas Witzke / Abraxas-Verlag

Click Here for Larger Londonite Image in a New Browser Window Images:

Click Here for Larger Londonite Image Londonite Comments: A yellow , lustrous, well developed londonite crystal 1.2 cm. on matrix. Location: Antandrokomby, Sahatany valley, Madagascar.Scale: Crystal size 1.2 cm. © Sandro Maggia/Minernet.it

Londonite Crystallography

Help on Cell Dimensions: Cell Dimensions:

a = 7.3205, Z = 1; V = 392.30 Den(Calc)= 3.42

Help on Crystal System: Crystal System:

Isometric - HextetrahedralH-M Symbol (4 3m) Space Group: P 43m

Help on X Ray Diffraction: X Ray Diffraction:

By Intensity(I/Io): 2.9898(1)(211), 2.1132(0.7)(222), 2.441(0.5)(300,221),1.7759(0.4)(410,322), 1.9568(0.35)(321), 3.276(0.35)(210), 2.208(0.3),

Click Here for Large Londonite Structure Window Crystal Structure:

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Help on Above

| | Taxer K J , Buerger M J , Zeitschrift fur Kristallographie , 125 (1967) p.423-436, The crystal struture of rhodizite, Note: name of mineral altered according to IMA decision in 1999, to name the Cs dominant phase: londonite, Locality: Manjaka, Madagascar | | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |

Physical Properties of Londonite

Help on Cleavage: Cleavage:

None

Help on Color: Color:

Colorless, White, Yellow.

Help on Density: Density:

3.34

Help on Diaphaneity: Diaphaneity:

Transparent

Help on Fracture: Fracture:

Brittle - Conchoidal - Very brittle fracture producing small, conchoidal fragments.

Help on Habit: Habit:

Euhedral Crystals - Occurs as well-formed crystals showing good external form.

Help on Hardness: Hardness:

8 - Topaz

Help on Luster: Luster:

Vitreous (Glassy)

Help on Streak: Streak:

white

Optical Properties of Londonite

Help on Gladstone-Dale: Gladstone-Dale:

CI meas= 0 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.024 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2026,KPDmeas= 0.2075,KC= 0.2075
Ncalc = 1.69 - 1.71

Help on Optical Data: Optical Data:

Isotropic, n=1.693.

Calculated Properties of Londonite

Help on Electron Density: Electron Density:

Bulk Density (Electron Density)=3.21 gm/cc
note: Specific Gravity of Londonite =3.34 gm/cc.

Help on Fermion Index: Fermion Index:

Fermion Index = 0.08
Boson Index = 0.92

Help on Photoelectric: Photoelectric:

PELondonite = 33.04 barns/electron
U=PELondonite x relectron= 106.21 barns/cc.

Help on Radioactivity: Radioactivity:

GRapi = 413.95 (Gamma Ray American Petroleum Institute Units)
Concentration of Londonite per GRapi unit = 0.24 (%)

Estimated Radioactivity from Londonite - barely detectable

Londonite Classification

Help on Dana Class: Dana Class:

25.08.02.02 (25)Anhydrous Borates Containing Hydroxyl or Halogen

(25.08)Dana Type

(25.08.02)Dana Group

25.08.02.01 Rhodizite (K,Cs)Al4Be4(B,Be)12O28 P 43m 4 3m

25.08.02.02 Londonite! CsAl4Be4(B,Be)12O28 P 43m 4 3m

Help on Strunz Class: Strunz Class:

06.GC.05 06 - BORATES

06.G - Heptaborates and other Megaborates

06.GC -Tekto-dodecaborates

06.GC.05 Rhodizite (K,Cs)Al4Be4(B,Be)12O28 P 43m 4 3m

06.GC.05 Londonite! CsAl4Be4(B,Be)12O28 P 43m 4 3m

Other Londonite Information

Help on References: References:

NAME( AmMin, Vol 87, p 356) PHYS. PROP.(AmMin, Vol 87, p 356) OPTIC PROP.(AmMin, Vol 87, p 356)

Help on See Also: See Also:

Links to other databases for Londonite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - GeoScienceWorld
4 - Google Images
5 - Google Scholar
6 - Handbook of Mineralogy (MinSocAm)
7 - Handbook of Mineralogy (UofA)
8 - MinDAT
9 - Mineralienatlas (Deutsch)
10 - Online Mineral Museum
11 - QUT Mineral Atlas
12 - Ruff.Info

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Print or Cut-and-Paste your Londonite Specimen Label here :

Londonite

CsAl4Be4(B,Be)12O28
Dana No: 25.08.02.02 Strunz No: 06.GC.05
Locality:

Notes: