Hydromagnesite Mineral Data
General Hydromagnesite Information
Chemical Formula:
Mg5(CO3)4(OH)2•4(H2O)
Composition:
Molecular Weight = 467.64 gm
Magnesium 25.99 % Mg 43.09 % MgO
Hydrogen 2.16 % H 19.26 % H2 O
Carbon 10.27 % C 37.64 % CO2
Oxygen 61.58 % O
______ ______
100.00 % 100.00 % = TOTAL OXIDE
Empirical Formula:
Mg5 (CO3 )4 (OH)2 •4(H2 O)
IMA Status:
Valid Species (Pre-IMA) 1835
Locality:
Castle Point, Hoboken, Hudson County, New Jersey, USA Link to MinDat.org Location Data.
Name Origin:
Named after its chemical composition.
Name Pronunciation:
Hydromagnesite + Pronunciation
Synonym:
ICSD 920
PDF 25-513
Hydromagnesite Image
Images:
Images:
Hydromagnesite Crystallography
Axial Ratios:
a:b:c =1.1308:1:0.9373
Cell Dimensions:
a = 10.11, b = 8.94, c = 8.38, Z = 2; beta = 114.58° V = 688.78 Den(Calc)= 2.25
Crystal System:
Monoclinic - Prismatic H-M Symbol (2/m) Space Group: P 21 /c
X Ray Diffraction:
By Intensity(I/Io ): 5.79(1), 2.899(0.82), 9.2(0.39),
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Physical Properties of Hydromagnesite
Cleavage:
{010} Perfect, {100} Distinct
Color:
Colorless, White.
Density:
2.16 - 2.2, Average = 2.18
Diaphaneity:
Transparent
Fracture:
Uneven - Flat surfaces (not cleavage) fractured in an uneven pattern.
Habit:
Acicular - Occurs as needle-like crystals.
Habit:
Encrustations - Forms crust-like aggregates on matrix.
Hardness:
3.5 - Copper Penny
Luminescence:
Fluorescent, Short UV=green, Long UV=bluish white.
Luster:
Silky
Magnetism:
Nonmagnetic
Streak:
white
Optical Properties of Hydromagnesite
Gladstone-Dale:
CI meas = -0.055 (Good) - where the CI = (1-KPDmeas /KC ) CI calc = -0.022 (Excellent) - where the CI = (1-KPDcalc /KC )
KPDcalc = 0.2363,KPDmeas = 0.2439,KC = 0.2311 Ncalc = 1.5 - 1.52
Optical Data:
Biaxial (+), a=1.523, b=1.527, g=1.545, bire=0.0220, 2V(Calc)=52, 2V(Meas)=30-90. Dispersion none.
Pleochroism (x):
none.
Pleochroism (y):
none.
Pleochroism (z):
none.
Calculated Properties of Hydromagnesite
Electron Density:
Bulk Density (Electron Density)=2.29 gm/cc note: Specific Gravity of Hydromagnesite =2.25 gm/cc.
Fermion Index:
Fermion Index = 0.02 Boson Index = 0.98
Photoelectric:
PEHydromagnesite = 0.77 barns/electronU=PEHydromagnesite x r Electron Density= 1.76 barns/cc.
Radioactivity:
GRapi = 0 (Gamma Ray American Petroleum Institute Units) Hydromagnesite is Not Radioactive
Hydromagnesite Classification
Dana Class:
16b.07.01.01 (16b) Carbonates - Hydroxyl or Halogen
(16b.07) Dana Type
(16b.07.01) Dana Group
16b.07.01.01 Hydromagnesite Mg5(CO3)4(OH)2•4(H2O) P 21 /c 2/m
16b.07.01.02 Widgiemoolthalite (Ni,Mg)5(CO3)4(OH)2•4-5(H2O) P 21 /c 2/m
Strunz Class:
05.DA.05 05 - CARBONATES (NITRATES)
05.D - Carbonates with Additional Anions, with H2O
05.DA -With medium-sized cations
05.DA.05 Dypingite Mg5(CO3)4(OH)2•5(H2O) Unk. Mono
05.DA.05 Giorgiosite Mg5(CO3)4(OH)2•5(H2O) ? Mono
05.DA.05 Hydromagnesite Mg5(CO3)4(OH)2•4(H2O) P 21 /c 2/m
05.DA.05 Widgiemoolthalite (Ni,Mg)5(CO3)4(OH)2•4-5(H2O) P 21 /c 2/m
Other Hydromagnesite Information
References:
NAME( Duda&Rejl90) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Ford32)
See Also:
Links to other databases for Hydromagnesite :
1 - Am. Min. Crystal Structure Database
2 - Amethyst Galleries' Mineral Gallery
3 - Athena
4 - EUROmin Project
5 - Ecole des Mines de Paris
6 - GeoScienceWorld
7 - Google Images
8 - Google Scholar
9 - Handbook of Mineralogy (MinSocAm)
10 - Handbook of Mineralogy (UofA)
11 - MinDAT
12 - Mineralienatlas (Deutsch)
13 - Online Mineral Museum
14 - QUT Mineral Atlas
15 - Ruff.Info
16 - WWW-MINCRYST
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Hydromagnesite
Mg5(CO3)4(OH)2•4(H2O)
Dana No: 16b.07.01.01 Strunz No: 05.DA.05
Locality:
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