Helvite Mineral Data

General Helvite Information

Chemical Formula:

Mn4Be3(SiO4)3S

Composition:

Molecular Weight = 555.10 gm

Manganese 39.59 % Mn 51.12 % MnO

Beryllium 4.87 % Be 13.52 % BeO

Silicon 15.18 % Si 32.47 % SiO₂

Sulfur 5.78 % S 5.78 % S^2-

- % S -2.88 % -O=S

Oxygen 34.59 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Mn²⁺₄Be₃(SiO₄)₃S

Environment:

Found in skarns, pegmatites, and hydrothermally altered rocks.

IMA Status:

Valid Species (Pre-IMA) 1817

Locality:

Schwarzenberg and Breitenbrunn, Germany. Link to MinDat.org Location Data.

Name Origin:

From the Greek helios - "sun."

Name Pronunciation:

Helvite

Helvite Image

Images:

Helvite Rhodochrosite

Comments: Yellow crystals of helvite on quartz and pink rhodochrosite.
Location: Galerie Elisabeth, Cavnic, Maramures, Romaina. Scale: Not Given.
© Lou Perloff / Photo Atlas of Minerals

Images:

Helvite

Comments: Large (for the species), triangular yellowish creamy colored crystals of helvite on white, albite matrix.
Location: Navegador mine, Conselheiro Pena, Minas Gerais, Brazil. Scale: Crystal size 0.7 x 0.7 cm.
© Fabre Minerals

Helvite Crystallography

Cell Dimensions:

a = 8.294, Z = 2; V = 570.55 Den(Calc)= 3.23

Crystal System:

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

$Help on X Ray Diffraction:$ X Ray Diffraction:

By Intensity(I/I_o): 3.386(1), 1.9549(0.34), 2.623(0.12),

Crystal Structure:

Mouse
drag1 - LMB Manipulate Structure
drag2 - RMB Resize/Rotate
Keyboard
S - Stereo Pair on/off
H - Help Screen
I - Data Info
A - Atoms On/Off
P - Polyhedra On/Off
B - Bonds On/Off
Help on Above

Hassan I , Grundy H D , American Mineralogist , 70 (1985) p.186-192, The crystal structures of helvite group minerals, (MnFeZn)8(Be6Si6O24)S2

View Additional jPOWD Structure files for Helvite
[1] [2] [3] [4] [5] [6]

Physical Properties of Helvite

Cleavage:

{111} Indistinct, {111} Indistinct, {111} Indistinct

Color:

Brown, Brownish yellow, Gray, Yellow, Yellow green.

Density:

3.16 - 3.36, Average = 3.26

Diaphaneity:

Translucent to opaque

Fracture:

Brittle - Generally displayed by glasses and most non-metallic minerals.

Habit:

Massive - Uniformly indistinguishable crystals forming large masses.

Hardness:

6-6.5 - Orthoclase-Pyrite

Luminescence:

Fluorescent, Short UV=deep red, Long UV=deep red.

Luster:

Vitreous - Resinous

Streak:

grayish white

Optical Properties of Helvite

Gladstone-Dale:

CI meas= -0.127 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= -0.138 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2283,KPDmeas= 0.2262,KC= 0.2007
Ncalc = 1.63 - 1.67

Optical Data:

Isotropic, n=1.728-1.747.

Calculated Properties of Helvite

Electron Density:

Bulk Density (Electron Density)=3.12 gm/cc
note: Specific Gravity of Helvite =3.26 gm/cc.

Fermion Index:

Fermion Index = 0.05
Boson Index = 0.95

Photoelectric:

PE_Helvite= 11.15 barns/electron
U=PE_Helvite x rElectron Density= 34.82 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Helvite is Not Radioactive

Helvite Classification

Dana Class:

76.02.04.01 (76)Tectosilicate Al-Si Framework

(76.02)Feldspathoids and related species

(76.02.04)Helvite group

76.02.04.01 Helvite Mn4Be3(SiO4)3S P 43n 4 3m

76.02.04.02 Danalite Fe4Be3(SiO4)3S P 43n 4 3m

76.02.04.03 Genthelvite Zn4Be3(SiO4)3S P 43n 4 3m

Strunz Class:

09.FB.10 09 - SILICATES (Germanates)

09.F - Tektosilicates without Zeolitic H2O

09.FB -Tektosilicates with additional anions

09.FB.10 Bicchulite Ca2Al2SiO6(OH)2 I 43m 4 3m

09.FB.10 Danalite Fe4Be3(SiO4)3S P 43n 4 3m

09.FB.10 Hauyne (Na,Ca)4-8Al6Si6(O,S)24(SO4,Cl)1-2 P 43n 4 3m

09.FB.10 Genthelvite Zn4Be3(SiO4)3S P 43n 4 3m

09.FB.10 Helvite Mn4Be3(SiO4)3S P 43n 4 3m

09.FB.10 Lazurite Na3Ca(Al3Si3O12)S P 43n 4 3m

09.FB.10 Kamaishilite Ca2Al2SiO6(OH)2 I-lattice Tetra

09.FB.10 Nosean Na8Al6Si6O24(SO4) P 43m 4 3m

09.FB.10 Sodalite Na8Al6Si6O24Cl2 P 43n 4 3m

09.FB.10 Tugtupite Na4AlBeSi4O12Cl I 4 4

09.FB.10 Tsaregorodtsevite N(CH3)4AlSi5O12 I 222 2 2 2

Other Helvite Information

References:

NAME( Duda&Rejl90) PHYS. PROP.(www.saint-hilaire.ca) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Helvite :
1 - Alkali-Nuts(English)
2 - Alkali-Nuts(Francais)
3 - Am. Min. Crystal Structure Database
4 - Athena
5 - CalTech Mineral Spectroscopy
6 - EUROmin Project
7 - Ecole des Mines de Paris
8 - GeoScienceWorld
9 - Google Images
10 - Google Scholar
11 - Handbook of Mineralogy (UofA)
12 - MinDAT
13 - Mineralienatlas (Deutsch)
14 - Online Mineral Museum
15 - QUT Mineral Atlas
16 - Ruff.Info
17 - WWW-MINCRYST

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Ask about Helvite here :
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Mindat.org's Discussion Groups
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Mineral Discussion Forum from Fabre Minerals - also available in Español

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

Helvite

Mn4Be3(SiO4)3S
Dana No: 76.02.04.01 Strunz No: 09.FB.10
Locality:

Notes: