Humite Mineral Data
General Humite Information
Chemical Formula:
(Mg,Fe++)7(SiO4)3(F,OH)2
Composition:
Molecular Weight = 538.58 gm
Magnesium 23.69 % Mg 39.29 % MgO
Iron 18.15 % Fe 23.34 % FeO
Silicon 15.64 % Si 33.47 % SiO2
Hydrogen 0.09 % H 0.84 % H2 O
Oxygen 37.13 % O
Fluorine 5.29 % F 5.29 % F
- %
F -2.23 % -O=F2
______ ______
100.00 % 100.00 % = TOTAL OXIDE
Empirical Formula:
Mg5.25 Fe2+ 1.75 (SiO4 )3 F1.5 (OH)0.5
Environment:
Commonly interlayered with clinohumite.
IMA Status:
Valid Species (Pre-IMA) 1813
Locality:
Mte. Somma, Vesuvius, Italy. Link to MinDat.org Location Data.
Name Origin:
Named for Abraham Hume (1749-1838), English connoisseur and collector of works of art, precious stones and minerals.
Name Pronunciation:
Humite
Synonym:
ICSD 34847
PDF 12-755
Humite Image
Images:
Humite Crystallography
Axial Ratios:
a:b:c =0.4943:1:0.2285
Cell Dimensions:
a = 10.243, b = 20.72, c = 4.735, Z = 4; V = 1,004.93 Den(Calc)= 3.56
Crystal System:
Orthorhombic - Dipyramidal H-M Symbol (2/m 2/m 2/m) Space Group: P nma
X Ray Diffraction:
By Intensity(I/Io ): 2.256(1), 1.479(0.7), 2.438(0.7),
Physical Properties of Humite
Cleavage:
{001} Poor
Color:
Brown, Yellow, White, Dark orange.
Density:
3.1 - 3.2, Average = 3.15
Diaphaneity:
Transparent to translucent
Fracture:
Conchoidal - Uneven - Uneven fracture producing small, conchoidal fragments.
Hardness:
6-6.5 - Orthoclase-Pyrite
Luster:
Vitreous (Glassy)
Streak:
white
Optical Properties of Humite
Gladstone-Dale:
CI meas = -0.028 (Excellent) - where the CI = (1-KPDmeas /KC ) CI calc = 0.09 (Poor) - where the CI = (1-KPDcalc /KC )
KPDcalc = 0.1796,KPDmeas = 0.203,KC = 0.1974 Ncalc = 1.61 - 1.7
Optical Data:
Biaxial (+), a=1.607-1.643, b=1.619-1.653, g=1.639-1.675, bire=0.0320, 2V(Calc)=70-78, 2V(Meas)=68-81. Dispersion weak, r > v.
Pleochroism (x):
pale golden yellow or deep golden yellow.
Pleochroism (y):
pale yellow or colorless.
Pleochroism (z):
golden yellow or pale yellow.
Calculated Properties of Humite
Electron Density:
Bulk Density (Electron Density)=3.09 gm/cc note: Specific Gravity of Humite =3.15 gm/cc.
Fermion Index:
Fermion Index = 0.03 Boson Index = 0.97
Photoelectric:
PEHumite = 6.53 barns/electronU=PEHumite x r Electron Density= 20.20 barns/cc.
Radioactivity:
GRapi = 0 (Gamma Ray American Petroleum Institute Units) Humite is Not Radioactive
Humite Classification
Dana Class:
52.03.02c.01 (52) Nesosilicate Insular SiO4 Groups and O, OH, F, and H2O
(52.03) with cations in [6] coordination only
(52.03.02c) Humite group (Humite series)
52.03.02c.01 Humite (Mg,Fe)7(SiO4)3(F,OH)2 P nma 2/m 2/m 2/m
52.03.02c.02 Leucophoenicite Mn7(SiO4)3(OH)2 P 21 /a 2/m
52.03.02c.03 Manganhumite (Mn,Mg)7(SiO4)3(OH)2 Pbnm 2/m 2/m 2/m
52.03.02c.04 Chegemite ! Ca7(SiO4)3(OH)2 Pbnm 2/m 2/m 2/m
Strunz Class:
09.AF.50 09 - SILICATES (Germanates)
09.A - Nesosilicates
09.AF -Nesosilicates with additional anions;
09.AF.50 Manganhumite (Mn,Mg)7(SiO4)3(OH)2 Pbnm 2/m 2/m 2/m
09.AF.50 Humite (Mg,Fe)7(SiO4)3(F,OH)2 P nma 2/m 2/m 2/m
09.AF.50 Chegemite ! Ca7(SiO4)3(OH)2 Pbnm 2/m 2/m 2/m
Other Humite Information
References:
NAME( Dana8) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Heinrich65)
See Also:
Links to other databases for Humite :
1 - Am. Min. Crystal Structure Database
2 - Amethyst Galleries' Mineral Gallery
3 - Athena
4 - EUROmin Project
5 - Ecole des Mines de Paris
6 - Franklin Minerals(Dunn)
7 - GeoScienceWorld
8 - Google Images
9 - Google Scholar
10 - Handbook of Mineralogy (MinSocAm)
11 - Handbook of Mineralogy (UofA)
12 - MinDAT
13 - Mineralienatlas (Deutsch)
14 - Online Mineral Museum
15 - QUT Mineral Atlas
16 - Ruff.Info
17 - Scandinavian mineral gallery
18 - University of Colorado - Mineral Structure Data
19 - WWW-MINCRYST
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Print or Cut-and-Paste your Humite Specimen Label here :
Humite
(Mg,Fe++)7(SiO4)3(F,OH)2
Dana No: 52.03.02c.01 Strunz No: 09.AF.50
Locality:
Notes:
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