General information
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| Chemical
Formula: |
(K,Cs)Al4Be4(B,Be)12O28 |
| Composition: |
Molecular Weight = 778.83 gm |
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Cesium 4.27 % Cs 4.52 % Cs2O |
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Potassium 3.77 % K 4.54 % K2O |
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Beryllium 8.10 % Be 22.48 % BeO |
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Aluminum 13.86 % Al 26.18 % Al2O3 |
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Boron 12.49 % B 40.22 % B2O3 |
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Oxygen 57.52 % O |
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______ ______ |
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100.00 % 97.95 % = TOTAL OXIDE |
| Empirical
Formula: |
K0.75Cs0.25Al4Be412(B0.75)12(Be0.25)O28 |
| IMA
Status: |
Approved IMA 1965 |
| Locality: |
Sahanivotry, Sahatany Valley, Madagascar. |
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Rhodizite Image
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 |
Several
gemmy crystals of Rhodizite frozen in a feldspar matrix.
Sahanivotry, Sahatany Valley, Madagascar.
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Crystallography
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| Cell
Dimensions: |
a = 7.317, Z = 1; V = 391.74 Den(Calc)=
3.30 |
| Crystal
System: |
Isometric - Hextetrahedral H-M
Symbol (-4 3m) Space Group: P43m- |
| X Ray
Diffraction: |
By Intensity(I/Io): 2.983(1)
2.44(0.5) 3.27(0.5) |
| |
Physical Properties
|
| Cleavage: |
[???] Indistinct |
| Color: |
colorless, grayish, yellow, yellowish
white, or white. |
| Density: |
3.44 |
| Diaphaniety: |
Transparent to Translucent |
| Fracture: |
Conchoidal - Fractures developed in
brittle materials characterized by smoothly curving surfaces, (e.g.
quartz). |
| Hardness: |
8.5 - Chrysoberyl |
| Luster: |
Vitreous - Adamantine |
| Streak: |
white |
| |
Optical Properties
|
| Optical
Data: |
Isotropic, n=1.6935. |
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Classification
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| Dana
Class: |
Anhydrous Borates Containing Hydroxyl or
Halogen |
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Dana Type |
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Dana Group |
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- 25.8.2.1 Rhodizite
(K,Cs)Al4Be4(B,Be)12O28 P43m- -4 3m
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- (Cs,K)Al4Be4(B,Be)12O28
P43m- -4 3m
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| Strunz
Class: |
Nitrates, Carbonates
and Borates |
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Shelly borates with
[BO2]1- to [B6O10]2- |
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Nitrates, Carbonates
and Borates [Shelly borates with [BO2]1- to [B6O10]2- {Hambergite -
Rhodizite series}] |
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- Hambergite
Be2BO3(OH) Pbca 2/m 2/m 2/m
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|
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- Rhodizite
(K,Cs)Al4Be4(B,Be)12O28 P43m- -4 3m
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